The numbers you are asking about should do fine in a 10g with 3 corydoras cats.
I wouldn't advise even bristlenose plecos for a 10g just because of their size and bioload. Being as bulky as they are they produce more waste than would be good for a 10g tank to try to support, in my opinion.
I also agree with RK, unless you have a large
sump or system going having hundreds of them in a 10g wouldn't be something you would see a whole lot of success with, without having the knowledge of how to handle such a tank. (More of a whole-saler tank setup there, rather than a hobbyists tank, I think.)