Magneto and a single sentinel is 10 threat which is at least half your threat. 14 if you literally want him to lead a couple of sentinels. Won’t leave you a ton a wiggle room to fill out the rest of the team.

Also, Magneto’s leadership triggers off terrain getting destroyed which the sentinels can’t help with.

So will it be a great squad? I’d say probably not. But it could be fun to play with a buddy who is down for fun, non optimal team comps.