The "art" in making a historical wargame (for me of course) is to find the balance between what we know of history and making the game fun to play. Late Republican Romans vs a Gallic army is a perfect case. The ++ POA the legionaries were getting against the majority of Gallic BGs, while (agruably) a historic result, did not make for a fun game; for either the Gallic player or the Roman. Superior legionaries, armored, drilled, with SSW gives them plenty of advantage in combat but still allows for a "chance" for the poor Gallic warrior at the "new" + POA. It is now up to Vercingetoix to use his greater numbers and good cavalry to "risk it all" against Caesar. Hmmmmmm ... Greater numbers and good cavalry ... Sounds like Alesia maybe.
Another interesting twist to the Gallic (barbarian) vs Roman match is BG size. 8-12 base Gallic BGs vs 4 base Roman BGs can be, and in my case usually is, problamatic for the Romans. 6's for the Roman goes a long way to help them stay around in combat but then you sacrifice flexability by having fewer BGs ... I
FoG-R, which everyone raves about, sets most BG sizes. I can live with that ... but FoG-AM offers the player more options and decision on BG size. Another interesting challange for AM players.
I can't stress the importance of army size and table size. So many of the rules problems go away with smaller tables (and in the case of 28mm, smaller armies). If you read Madaxman's battle reports, and who doesn't ??

..... Some of the terrain he has to fight over is bordering on stupid, terrain no general would choose to fight on. So maybe there-in lies an area that FoG (both) needs to sort out. We seldom use the terrain rules as written, although I understand the need for these rules in tournaments. Two weeks ago we fought a 650 point Athenian v Spartan hoplite-heavy battle. One flank was a beach, with a couple cool 28mm triremes laying there for looks. The other flank was rocky ground and a temple on a hill. The area between ... the hoplite arena. Historical note, we use 1"=1MU ... not 40mm, all on a 6x4 table. Great game ... except I lost. The Ephors will not be pleased.
Mike B