Well, as-is, against an equal opponent(oh god please don't let NPCs get personality traits rolled for their gladiators that could help them), you have a 50-50 chance of winning, period. Usually coming down to who missed a swing or who took initiative in the last round. At this point, just luck. Which I'm actually okay with, since eventually it won't be. As much, at least.
NPC's during non-leagues do not get traits. Leage NPC's do. And luck will stop being a factor in about... however long it takes you to earn a second gladiator spot.
EDIT: On another note, I have a question. Is it possible to gain fame if you lose in a spectacularly crowd-pleasing way? And also, how fast is the power-curve do you think? I mean, for how long would 'Blacksmith' as a Lord have made a difference? At this level, of course, it's a huge deal, with how little damage everyone does, but since it's not anything like +10% armor, it's a little weaker.
You usually gain fame so long as the match wasn't a complete bore-fest. You probably won't gain as much fame however. The power-curve is... Somewhat fast at the start but slows down a lot near the end. Just for a fun fact the Squire > Angle tree requires [80] > [475] > [950] > [1600]. Which seems hefty but you'll also be having them in more and tougher fights. But that doesn't change the fact that they'll be leveling somewhat slowly afterwards. The damage/health is something akin to [25/100] [50/150] [75/200] [100/225] so take from that what you will. The Angel does have a Death Ward and a Air ward but... Yeah.
Blacksmith lord will make a difference eternally, just like Merchant will. All the Lord types should be semi balanced. In theory it's possible for certain units to hit armor cap naturally [Armor cap being 95, just FYI] though they usually have lower health.
Though I think you might misunderstand what +10 armor does. It doesn't subtract 10 damage, it subtracts 10% of the damage. It's just easier for me to type 10 than 10% in the armor section.
Armor only negates damage from weapon sources, right?
No, Armor absorbs from all sources, aside from Life. However, no offensive Life abilities exist in this game. To my knowledge. Lemme recheck...
Nope, no offensive life skills. Life is mostly buffs and such...
Did I uh... actually answer your questions... I feel like I may have veered off the track.