imo,this is not the ultimate build.

weakness:
1.no auto-haste,therefore low speed.
2.more importantly,no math skill,therefore slower kill rate.

i would agree that this is one hell of a powerful build,but i am led to believe that this is not the ultimate.
Auto-Haste is definetly a plus, but if i equipped the Excalibur in place of the Rune Sword my magic attacks will take a beating, while my sword attacks will only go up a bit. I don't know why they don't go up more than than they do, but IMO, having the stronger magic over the stronger attack w/o haste is better...as i generally already have at least 2 auto-hasted units in battle. Not to mention, Scream will get my speed up in no time.
Math skill, although a highly effective skill, does not belong in the hands of a Squire or any job class other than that of a Wizard/Priest/Time Mage/Oracle/Summoner. Even though I have MA+ items, it isn't enough to render Math Skill effective. Besides, my Summoner has Math Skill set to her secondary...and that makes for a truely wonderful machine of slaughter and mayhem.
(i suppose it'd be more accurate to say it's the ultimate build, for me...it has what i want to be sure)

p.s. I once made Ramza a Mime (first Mime ever at the time), and while it took a bit of time to get used to using a Mime, he was devistating once I figured him out and learned to use him quite effectively.