I haven't played enough times to speak to balancing, but the first charge does seem like an advantage. My train of thought ran more toward making melee combat simultaneous (both sides roll and deal damage to each other.) That might cause some balance issues in the other direction though since the troops' wounds/defensive special abilities are defined with the rules as written in mind.
Some sort of simultaneous damaging in battle would allow the first player to still have some advantage by choosing where to initiate a charge, but would prevent overkilling a defending unit and taking them out of the game without a chance to act.
That's my other thought. I only have played this system once and that was with the pre-set army lists in the Orcs/Elves set. Building an army with an appropriate mix of charge-catchers, bruisers, ranged, and command/special units seems to be a source of depth in these games.
I've found that the first-player advantage goes away strongly when you play with more points. 60-point games are very swingy and there's a strong potential first-player advantage. As you add more points, it's harder for the first player to get a massive first-attack advantage.