Malak is a Hebrew name, so that would suggest Shemite, but Malak certainly didn't appear to be Shemite. Most likely Kothite, with a mix of Shemite and Hyborian ancestry.
Bombatta was, as far as I could tell, a made-up name vaguely African sounding. Wilt Chamberlain was, of course, African American. I'd say Zembabwei or one of the tribes of the southern Black Kingdoms; maybe even a far-wandering Southern Islander.