Scarlet Witch , Dr.Strange, Thor, Rulk, Magneto, Tony Stark , Vision, Iceman and Sersi are enough to get the job done
Thor, SW, DR Strange and Tony are underestimated....
Thor is a God, SW and Strange are one of the most powerful beings in the Universe..for god sakes.
Add Prof X and imo you got it perfect
@dondave: Sorry to but in. But Seeing that they are the ones invading Tony should be prepped enough to at least survive if nothing else. Tony Stark on a planet with highly advanced technology? Sounds more like a vacation to me.