Orcs are a fun faction but they are a bit riskier to play because they don't have a lot of Courage boosters (and no, I Kill You Meself isn't enough. Although it is a great card, there still is only 2 of them in the deck).
Lash is a great ability, but the key is to remember its really an MC boost with an attack cookie. Once you're engaged, you shouldn't use it. Ever. Which is okay because the Orc command cards are good. My one gripe on them is that I dislike cards that require a Command Action to play. This menas you should draw your command cards one at a time. Because if you decide to draw CCs with all your CAs, then grab 4 at once only to find the second card is a really good card that requires a CA, then its basically a dead card.
I'll be cute and break down the Orc units into the Good, the Bad, and the Ugly.
The Good
(i.e. build your army around these cards)
Goblin Bowmen: some folks think they're no good, but that really depends on what you're trying to do. If you want super-accurate sniper like shooting...play elves. Seriously. But if you want Walmart shooting (i.e. points spent on shooting and nothing else) then these are your guys. They have the majority of points spent on their shooting dice, with minimal points spent on things like defense, courage, hit boxes, etc.
Goblin Raiders + Crazed Goblins: I pair these two unit types because they are better than the sum of their parts. I run them in a trio of 2 Goblin Raiders backed up by a single Crazed Goblin unit. This combo is ~100 pts cheaper than 2 Orc Swordsmen units and can give you similar tankyness. If you're facing someone who's fielding a lot of 150-200 pt units, this combo will hold the line for you for some time.
Orc Swordsmen: Tanks for when someone is putting out 200+ units, that would eat your Raiders+Crazed Gobbos as a snack. A lot of people poo-poo their Cge 12, but they're still a pretty decent tank even with that. My usual default build is 2 Orc Swordsmen for the relatively heavy hitters and 2 Goblin Raiders+Crazed Gobbos for the chump troops.
Goblin Wolf Riders: IMO, the best unit in the faction due to cost vs effectiveness. They're cheap and hit like a dropped building. These guys are usually the hammer in my default build to the anvil I mentioned above. In that role, I usually take 2 and have them run on the same flank. The first one is going to die horribly, leaving the second one to either clean up the weakened enemy or (if the enemy is destroyed) start rolling up the flank. If they're taken as flank defenders, I'll take 1 and hold them back, just daring someone to charge the flank of my line. Because with Lash, the Wolf Riders are AT&T (i.e. able to reach out and touch anyone).
Orc Axemen: Oh my lord these guys are sweet. I still say Wolf Riders are the best unit in the faction, but these guys are a close second. They're you're infantry breakthrough unit. Nuff said.
The Bad
(i.e. leave them in the box)
Goblin Bomb Chucker: Some people love this unit, and I really want to love them as well, but I just can't. The Extreme range penalty combined with the no command cards just kills this unit. As is, its basically just a way to suck command cards off your opponent, with him playing Parry and such to deal with the occasional lucky number of shots. But 300 pts is just too expensive for that role, even if I was doing a stand and shoot. Now, if you love this unit, then by all means take it, but understand it's not really a good use of points. (not that that's every stopped me before

) If this unit was changed so that it treated Extreme Range as Long range, then I'd reassess my opinion of it.
Trolls: Wow what a craptastic unit. Even with the current stamp that it can regenerate into the Green from the Red, it's still a stay-in-the-box unit, which is sad because its a borderline iconic unit. The problem is that even with its high Courage it's still going to fail its 2nd rout check half the time. That means you're going to have 5-6 Red boxes that never get used. On most units, 1-3 unused red boxes isn't a big deal, but on this guy that is. Functionally, this unit becomes an 8 hit box unit and while its defensive stats look good, a Def 1/3 is only marginally better than a Def 2/2.
The Green-and-Red hit box idea IMO is just a failed experiment. It leaves too many Red boxes unused and the unit can go from 5 dice to 3 pretty quickly on what is supposed to be a breakthrough unit. I once ran an experiment where I costed out the unit at 5G 5Y 4R and it ended up coming in at like 5 pts more, for much more survivability. Now, the unit is taking its second cge check after 10 boxes instead of 8. Those 2 boxes means 2 extra turns of fighting, which is a big deal. With that tweak, and removing the stamp on regeneration, the unit comes close to being worth it.
The Ugly
(i.e. situationally useful)
Orc Marauders: I'm sure I hear folks howling that I've been hitting the crack pipe again, but I'll be honest: I don't think this unit is an "always take it." Oh yeah this guy is beefy, with loads of attacks, a great offensive skill, and a study Def 2/3. But I don't think its worth paying the extra 67 pts in every case. In most cases, Marauders and Axemen put out comparable amounts of damage. So really what you're paying for is the Def 2. And, IMO, if you're taking Orcs you already have a gambler's mentality with the fact that your tanks are Cge 12 and you only have 2 courage cards in the deck. So I'm not gonna hedge and spend points on defense when I can save a few points and go for more offense.
However, when I'm playing a fragile/skill faction, these guys come out. They're almost tailor made for going up against Elves, who usually have a combination of high skill and low-to-medium toughness and not a lot of damage boxes, but also have high offensive skill themselves. In that case, it's worth spending the 67 pts for that extra survivability to grind out against those Elder Blade High Elves. And thus, when a unit has times when you take 'em and times when you leave 'em in the box, that puts them in this category. With the caveat that they move into The Good depending on your opponent.
Orc Crossbowmen: If I plan to take a close & hose army, I usually leave these guys in the box. Yeah they're Pow 6, which is good vs high toughness guys, but then that crossbow attack is less useful. At which point I'll pay the extra 10% for the Axemen. However, if I'm playing with some terrain one which I plan to anchor my line, these guys can nab the terrain and shoot while the enemy tries to take that hill from me. Or if I'm building a stand and shoot list, at which point these guys are great buys. They are useful, if a bit tricky and a bit un-Orcy to use, but their useful is more about what is on the table and/or what you plan to do than their inherent value.
Orc Spearmen: I use Orc swordsmen as a tank unit, and this guy is getting expensive enough that he has to start doing some killing to be worth it. If I know my opponent is going to take some beefy monster or cavalry, then these guys are awesome flank protectors. Otherwise, they're something I upgrade my Swordsmen to if I have the spare points. Still good, mind you, just not the first thing I grab when I build a list.
Goblin Spearmen: Whereas the Marauders border on being in The Good category, these guys border on being in The Bad group. Goblins are there to die and spending more than you have to strikes me as sending good points after bad. Still, it is only 17 pts for that extra attack and so I do sometimes upgrade if I have less than 25 pts remaining. More than that and I'll pick up a card or upgrade Orc swordsmen to spearmen. Its rare that I'd upgrade this unit, but on the flip side, they can put a hurt on heavy cavalry. But really, these guys usually stay in the box unless I'm in a unique "I have 17 pts left over" situation or I know my opponent has lots of light cavalry that will be charging my for some fool reason.