Hmm jiraiya is from no known clan yet has sage mode
Minato is from no known clan yet has perfect sage mode
Kabuto has sage mode although he modified his body
One doesn't need to be a Uzumaki or senju to learn sage mode, just have enough chakra and skill.
Heck Naruto when even 3 tails couldn't defeat Orochimaru managed to learn Sage Mode at the time, it doesn't set the bar that high learning sage mode.
For sage mode it requires high chakra, strong body and talent.
Sasuke was able to defeat team 7 physically when Naruto went to orochimaru lair
Sasuke chakra surpassed jubi madara after VOTE2
Sasuke got talent in Curse seal noted by juugo when Sasuke did partial transformation
I am on my mobile sorry if my post doesn't look good.
Because Jiraiya's SM was imperfect, so was Minato's (he even stated he was horrible at kneading senjutu) and Kabuto literally modified his body with multiple clan's KKG to be compatible with SM. Fukasaku even said Naruto suprassed Minato and Jiraiya in mastering SM. If achieveing SM is that easy, Madara with all his infinite knowledge would have done it, obviously that wasn't the case.
Sasuke was given a by product (CM) and applied it. Its like when Naruto gave the SA chakra, and they all gained cloaks, it doesnt neccesarily mean they can tame Kurama's chakra to its fullest, just that they can use what was given. Molding your chakra with NE is entirely different from using a by product successfully. Even If SM was possible for Sasuke, it would be a very inferior version to Naruto's as he lacks the genetical make up for it. Its like If Naruto weilded Rinnegan, the power scale of his rinne techs would be down a notch as he lacks the powerful chakra Indra's lineage is known for.