A toadstool would most likely be bothered.
I also do not like the idea of host nems in smallish tanks, too unstable, too close to pumps and PH's, many nems will be touching tank walls when full grown, and god forbid they try to move.
frog and hammer are awesome alternatives, and very "nemmy" looking.
Most clowns will gladly accept them w/out issues to either host or guest.