pill bugs are actually very beneficial to most reptile enclosures. i have a pretty good size colony going in my croc skink tank and they clean the substrate for me. and it wont hurt the lizards if they decide to snack on a few, lol. i think they would be fine in a tortoise enclosure, especially if you are using a substrate like coco fiber or any thing loose like that.
pill bugs, sow bugs, rolly pollys. all the same. all mine were wild caught and quarantined before introducing them. they have reproduced quite a bit and so im not even sure how many are in there. but i started with about 30 or so.
Actually Pill and Sow bugs are different species. Pills can roll up and have more of a dome shape, like tiny, very short millipedes. Sow bugs are flattened and incapable of rolling. They also move faster than pills. Either species works fine as cleanup crews in natural tanks.