King David.
Boudica definitely. That’d be awesome.
Ooh, give us Zenobia!
Another one… Ramesses the Great… or another famous Egyptian Pharaoh.
I have a soft spot for Tomyris myself. Not sure if she fought personally, but leading an army against Cyrus and winning’s nothing to scoff at.
I`ll second that request on Zenobia.
On the importance of good stats I have to say:
We were playing with my new level 1 party today when they met some 6 goblins. One round later 3 gobbos and the party fighter were dead so Dolm the level 0 torchbearer took his strength of 5 and the polearm they had given him and went on to slaughter the other three goblins including their champion, one per round while the party stood there being generally useless and not hitting anything.
So of course its one thing to do this once and another to do it from Greece to India but skills will only get you so far without luck. I guess what Im saying here is that in my opinion 2 - 3 18`s would have been enough but 4 is fine too.
I`m more interested in the choice of proficiencies anyway and those look right on to me. 
I second King David (Fighter or Explorer - most likely the latter) and Spartacus (Fighter). Maybe also Gideon (Fighter or Explorer).
King David actually followed the Adventurer, Conqueror, King paradigm quite well, starting out as a shepherd and later guerilla fighter against the Philistines, gaining henchmen and followers (his Mighty Men), then conquering Jebus and other cities,eventually replacing Saul as king and founding a dynasty.
It is really hard to gauge the comparative abilities of historic figures for a number of reasons. First of all, you have propaganda (sometimes from the supporters, sometimes from enemies). You never hear that a dude was a pretty good warrior who got some lucky breaks and had friends, no, it’s he’s always an unparalleled god of war! Furthermore, you tend to hear more about the great successes (potentially aided by a stroke of luck) than the more mundane actions. If a million men try the impossible, you will hear more about the one successful man than all the 999,999 failures combined.
Pompey doesn’t deserve to be on there, a man with great propaganda who often stole other men’s achievements, and barring two occasions didn’t face credible opposition.
Lucius Licinius Lucullus does - one such man who’s achievements (in the East) were stolen by Pompey.
Quintus Sertorius does too - the one capable general before Caesar that Pompey faced in his time.
You could argue that many of Alexander’s warlords deserve to be on there, and some of their descendants too. Ptolemy, Antigonous One-Eye, Seleucus amongst others.