According to the ELH FAQ, your BAB is frozen when you hit CHARACTER level 20. So a level 17 monk with a template that gives ECL +3 is stuck at BAB +12 forever and gains only "Epic Attack Bonus" from then on and can never get a fifth attack?
The real arguemnet cam when you take 20 levels of Wizard followed by 20 levels of fighter, and compare that to a character who did that in reverse. One has 4 attacks, the other 2 even though their levels and classes are perfectly equal.
Lets say it takes you, on average, 6 months to gain each level. That seems a bit fast to me at epic levels, but not too terribly so in a ast-paced campaign of catastrophic proportions.
If that is the case, then you have been a fighter for ten more years than you've been a wizard. It sounds quite plausible to me that you would be a better fighter than the guy who spent the first ten years of his career studying books.
Now that i think about it, i'm not sure i like the epic advancement rules very much. I'd rather have it that you increase in the same manner that you have for the previous 20 levels, so a 40th level fighter is still twice as good at hitting things as is a 40th level wizard, instead of a third better.