I don't have Foundry Egyptians but do have Newline, Foundry and Warlord ( ex Cutting Edge Miniatures) Sea Peoples and Hittite figures and they do mix OK together size-wise. The Foundry figures are beautiful, as are Warlord's but I find the Newline cruder and less well-detailed. They also vary more within ranges. I think the Newline Hittites are very nice, their Sea Peoples are much less detailed. That said they are much, much cheaper. A Foundry chariot retails at ?18 whilst Newline are on sale until close-of-play this Sunday the 23rd at I think ?7 per chariot or ?18 for a pack of three. If you need a lot of chariots I would certainly look at their chariots/chariot runners and maybe spend extra on Foundry infantry. I have no experience of the Northstar figures but suspect they are bigger and heftier as the Foundry models are Perry sculpts going back to the late 1990s.