Revise? Amazons (for most of the usual reasons)
Rebuild from scratch? Khemri.
First thing: The name.
There is a human team, not an Altdorf team. There is a High Elf team, not a Lothern or Ulthuan team. There is Chaos Dwarf team, not a Zharr-Naggrund team. By any reasonable standard of consistency, the 'Khemri' team should be called either Tomb Kings or Nehekhara (For those unfamiliar with the relevant Warhammer geography, Khemri is the capital of Nehekhara). Numas, Zandri, Quatar, Mahrak & Lybaras (or to put it another way, the rest of Nehekhara) presumably play too.
Second thing: The history.
I'm not overly keen on the idea that the original game was a Slann/Khemri thing. On the plus side, it's a bit of a callback to a 1st or 2nd ed line which described Ramtut III as being a veteran of the original game. But it undermines what I consider to be one of the chief sources of humour in the Blood Bowl background: the idea that the excessive violence, mayhem and everything else that makes blood bowl so fun is all due to the misunderstanding of a (more or less) peaceful sport. Also ruins the NFL/Nuffle joke and leaves us with the mystery of where Amorica is.
Third thing: The names.
I'm a self confessed punner, and puns have always been a part of Blood Bowl. It would be a shame to see them lost completely. But Thro-Ra and Blitz-Ra are just ...

Fourth thing: The Warhammer connection.
I know, there's a lot of debate over how closely Warhammer and Blood Bowl should be tied, but it seems fairly clear to me that the intention has always been to parody or mock Warhammer first, football (of all varieties, but especaially the NFL) second, generic fantasy third and then pretty much anything else. I mean, the Khemri team wouldn't exist if Warhammer's Undead hadn't been split down the middle. So why do we have a team based on a mummy kingdom, which may or may not have mummies? Is a 'Tomb Guardian' a different sort of mummy? In Warhammer a Tomb Guard is basically a wight (when they split the undead, we got Tomb Guards for the Tomb Kings and wights (now Grave Guard) for the vampires, with identical stats). Isn't this a little bit pointlessly confusing for those who play both games? And it leaves us with the strange position of having a team based on a mummy themed and mummy led army without any players that are unambiguously mummies.
But more importantly, we missed the oppurtunity to grab an awesome new player type. The Ushabti. IMO the single coolest thing in the Tomb Kings army book. And having a distinctly egyptian styled animated statue on the lineup does a hell of a lot more to establish the right 'feel' for the team than tacking a '-Ra' suffix onto your positional skeletons.
So basically I like nothing at all about the current 'Khemri' team. Well, the models aren't bad, and their rules seem reasonable if uninteresting.
I say scrap the current lineup completely and change to something more like:
NEHEKHARAN TEAMS
0-16 Skeletons 40k 5 3 2 7 Regeneration, Thick Skull G/ASP
0-4 Tomb Guards 90k 6 3 3 8 Regeneration, Block GS/AP
0-2 Mummies 120k 3 5 1 9 Mighty Blow, Regeneration S/GAP
0-1 Ushabti 140k? 4 5 1 10 Stand Firm, Loner, Bonehead, Thick Skull, Juggernaut S/GAP
Just for the record, I do not use, nor do I have any intention of ever using, a Tomb King army or team (under any rules, including the ones I've slapped together here). I just see so many problems with the 'Khemri' team that I consider them a blight on one of my all time favourite games.