Howard / Cauley-Stein at the 5 would be fine for me. I'd also be fine with Boogie.
Bembry or McGruder would be solid as the final spot on the wing.
Smart / Pritchard
Brown / White / Bembry
Tatum / Brogdon
Horford / Gallinari / Hauser
R Williams / G Williams / Boogie
I list Grant as back-up 5, but knowing how we do subs it is unlikely that he'll spend an awful lot of time at the 5.
Lots of guys who can play multiple positions quite comfortably. All of Tatum, Brown, Smart, Brogdon, White and Horford are really strong in at least 2 spots, if not more. Even role players like Grant, Gallo and hypothetically Bembry could.