War tactics seem to be pretty variable as well, looking at the Xaela's in game stat distribution and the lack of mention of magic usage in combat, it seems they rely on a mixture of swarming, raw overpowering, archery, some javelin stuff and even some stuff with poison blowdarts. Even armor isn't completely unheard of look Qerel, who kill tigers with their own hands as a coming of age ceremony. Not every clan fights, but brute strength is definitely a wanted characteristic, looking at the Malqir's description "A western steppe tribe characterized by its unique leader-choosing ritual which, instead of the usual test of brawn, is a game of Kharaqiq--a chess-like game played on a circular board divided into three rings." The notation of a "Usual test of brawn" seems to indicate that strength is valuable, and it doesn't take too much of a leap in logic to assume that the "usual test of brawn" is well liked because "Brawn" is good for battle.
Even then, how would a tribe like the Buduga survive and succeed in battle if it was
that much of an issue?
Lots of factors are still unknown, but the Xaela tribes deploy a lot of diverse strategies to survive in the steppes, I wouldn't discount strength as much as you do.