If I'm to go by the SEG rules, the duo should handle Cell pretty easily. Going by my personal view using a 4x SSJ2 multiplier, Cell ends up being strong enough to take them both on.
ASSJ is the same boost as SSJ2 in my books, but MSSJ cannot get stronger by buffing their muscles. If we assume they get the same boost as Vegeta/Trunks post 1st rosat, it's overkill.