Why should the first 20 levels of fighter yield anything different depending on if it's your 21-40 levels or 1-20?
I agree with this statement, and it's one of the reasons that I have a few issues with a couple other Epic rules.
What about a 20 Fighter/20 Wizard? Because of the way Epic rules apply saves and attack bonuses, a character could have any of the following, depending on how they took their levels:
+30 Attack Bonus, and good Fort saves (20 levels of fighter, followed by 20 of mage)
+20 Attack Bonus, and good Will saves (20 levles of mage, followed by 20 of fighter)
+25 Attack Bonus, and medium Fort and Will saves (from switching off every other level. On a personal note, this is the one that I think any 20/20 Fighter/Wiz should be)
Basically, it just bothers me that a character with BAB as a fighter will lose some of the effectiveness of it if they multiclass into a class with BAB as a cleric or wizard during their first 20 levels, but face no penalties if they wait until level 21 to do it. Same thing for saves. Are there any rules out there that address this problem?