OK, I'll bite! Just keep in mind that I don't normally get into specific stats in new factions(I leave that to the pros) so many of my opinions may not be the greatest.
Core:
Barbarians: Offense: (4) 4/5 Defense: 1/1 Range:- Courage: 13 MC: 3.5” Health: 3-4-3
The standard, cheap core unit. Equipment: Leather armor, hand axe and mace."YEARRRGHHH!!"
I'm thinking that these guys are just pathetically weak to be what many would consider to be "stock" barbarians. I'd give them the generic (5) 5/5 stats. Unless you wanted to rename this unit something like "Youthful Barbarians" or whatever. Think Umenzi Initiates.
Bandits: Offense: (4) 4/4 Defense: 1/2 Range:- Courage: 11 MC: 3.5” Health: 3-4-2
When getting shot at, defence gets a +0/+1. MC becomes 5" when final rushing. Equipment: Dark Leather armor, spiked clubs. These dodgy bandits are experienced in the art of dodging arrows.
Neat ability, but still way too weak. At least raise the offensive stats to (5) 4/5 or something.
Axe Throwers: Offense: (5) 4/4 Defence:1/1 Range: 10.5" Courage: 11 MC: 3.5” Health: 3-4-2
Equipment: Leather armor and throwing axes. (+0) +1/+0 when engaged. Getting executed is bad enough, but when you get executed from afar...
I agree with a previous poster that 10.5 is way too long a range for thrown axes. Umenzi Javelineers only have a range of 3.5 and a javelin will fly a heck of a lot further than a throwing axe.
Maulmen: Offense: (5) 5/7 Defense:1/2 Range:- Courage: 12 MC: 3.5” Health: 4-4-3
(+1)+0/+0 when fighting cavalry. No Charge bonuses. Equipment: Leather Armor and maul. These mauls can really maul people- why are they called mauls for then?
Now we're talking! THIS is what I expect when I think Barbarians. Good upper level core unit.
Battleaxemen: Offense: (6) 5/6 Defense: 1/2 Range:- Courage: 12 MC: 3.5” Health: 4-4-3
Equipment: Leather armor and battleaxe. Woodcutters with a bunch of big axes.
Not bad. Basically Umenzi Berzerkers that can be given orders and face courage checks.
Fishermen: Offense: (5) 4/5 Defense: 1/2 Range: 3.5” Courage: 11 MC:3.5” Health: 3-3-3
Persistent. No charge bonuses. (+0) +1/+0 when fighting cavalry. Equipment: Leather armor, fishing rods improvised as whips. Even the fishermen are forced to take part in wars.
Hmm, I would downgrade the stats and make this the weenie unit. Unless it's the fishing rod of the gods, I would not fear one of these guys in a hand-to-hand fight myself. Actually, I don't care much for this as a fighting unit at all.
Standard:
Whippers: Offense: (5) 5/5 Defense: 2/1 Range: 5” Courage: 13 MC:3.5” Health: 4-4-3
Vengeful. No charge bonuses. (+0) +1/+0 when fighting cavalry. All units within a 5” range of the whippers get (+0) +0/+1 but must take a courage check. However, they get +2 courage for this courage check temporarily. “Move it! Stay in formation!”
This.... is interesting. It's like Umenzi leadership, but with a twist. I actually think this is a cool unit. Can you explain how they would be better against cavalry?
Flailers: Offense: (6) 6/6 Defense: 1/2 Range:- Courage: 13 MC: 3.5” Health: 4-4-4
Vengeful. Fearsome. No other unit may engage a unit engaged with flailers. Equipment: Flail, chainmail armor. No unit dares to interfere with these fearsome fighters.
Whoa, these guys are brutal in an offensive sense! Interesting caveat about engaging enemies alone. And of course, Flails are both unique to BG (so far) and are pretty cool.
Executors: Offense: (4) 4/8 Defense: 1/1 Range:- Courage: 12 MC:2.5” Health: 4-3-3
Persistent. No charge bonuses. Permanently on close and no command cards can be played while the executors are engaged. Berserk cannot be used on it. Equipment: Executor’s axe and leather armor. Deadly. I mean they are supposed to kill people, aren’t they?
Reminds me of an uncontrollable Dwarven Miner unit. OK.
Zealots: Offense: (7) 4/6 Defense: 2/2 Range:- Courage: - MC: 3.5" Health: 3-4-3
Never routs. Fearsome on the charge. Permanently on close. When assigning standing orders, an objective unit must be given. The zealots gets a (-1) -0/-0 and -1/-0 when engaged with a unit other than the objective unit. Equipment: Spiked flails, spiked maces, battleaxes, spiked clubs, etc.
Interesting offensive stats. And decent defensive stats (for the Barbarians). And stuff with spikes on them. Cool!
Elite:
Bull Cavalry: Offense: (6) 5/6 Defence: 2/2 Range:- Courage: 14 MC: 6” Health: 3-3-3
Cavalry. Vengeful. Terrifying on the charge. +1 impact hit while charging (adds on to the normal charging bonuses). Equipment: Flail and chainmail armor. Mount: Bull. Deadly in charges. Especially against red coloured opponents…
uh.... Barbarians on Bulls? Sorry, but that does not compute.

But the flavor text made me chuckle

Berserkers: Offense: (7) 5/7 Defense: 1/1 Range:- Courage: 15 MC: 3.5” Health: 4-4-3
Persistent. Fearsome. Berserk’s effects are (+1) +1/+1 and –1/-1. Equipment: Battleaxe, spiked mace and leather armor. Barabarians are brutal, zealots are vicious, executors are deadly, but berserkers are all three.
Insanely lop-sided unit when comparing their offensive ability to their defensive ability. OF course, I'm sure that's what you where aiming for. But I think it's still to heavily skewed. Perhaps make the offensive stats (6) 5/7 and the defensive stats 2/1 or 1/2? And I think YMG capped courage at 14.
Chieftains: Offense: (6) 6/6 Defense:2/3 Range:- Courage: 15 MC 3.5” Health: 5-4-5
Vengeful. Fearsome. Equipment: Chainmail armor, two mauls and battleaxes. Only elite berserkers or bull riders may become chieftains.
With offensive stats, defensive stats, and a health bar like that, these guys would be way up in the 400+ points value range. I'd make the offense (5) 6/6 to keep them in line with units like Chosen and Longbeards and maybe remove a red health box or two. And again, I believe YMG capped courage at 14.
Over all, this faction seems to be heavily skewed towards offense with little to offer in defense. This is not a bad thing, and it will probably make for short games. But I think this balancing issue within some of these units may make them awkward to use. One thing I do like is the introduction of Maces and Flails. I'm surprised that no other units in existing factions are armed with these.