Wow, I really didn't believe Veterancy as a concept would be capable of generating this much discussion: we already have dozens and dozens of promotions that I thought it relatively unnecessary. The Combat promotions, could easily be considered a sub-set of Veterancy, just as Drill and other promos could be considered a Veterancy sub-set for their particular troop type line. They all provide increased battle performance which is the point for me. Given that they're also generally received after earning XPs in combat, I'll just treat the current promos as falling under the umbrella term "Veterancy".
Now if FFH2 were claiming to accurately model combat in Erebus all its complexity and yet doing so in such a way as to amuse actual real-life FFH2 combat veterans who've felt the terror of being a new recruit facing a charge by heavily-armored Amurite knights or experienced the sudden shock as an Ljosalfar assassin rises like a phantom from the forest leaves, then I'd say yeah, we need to reflect combat as it really is. If Veterancy really did that, instead of just being yet another promotion, I'd welcome it too.