I kept my smasher with clowns, dottybacks, small wrasses, even a small trigger for awhile with no problems. Ide say it will come down to the behavior of the actual mantis you get and whether it gets real hungry or not.
I keep mine with lots of inverts. Its a spearer so it doesnt mess with most of them. Right now im taking a risk and trying a coral banded shrimp...the softest bodied creature ive dared to try...we will see.
If you get the zebra be ready to buy a big tank and have a 20" sand bed...