The real question isn't what technology people use to sustain multiple handles, but whether or not trolls should be booted off for taking the mickey.
If all that counts is number of posts, even with zero quality, then carry on as we are. In fact, why not expand it and create some bots with Artificial Stupidity to post even more hostile crap ?
Of course, I doubt going down that path creates much value, as any serious potential new members are likely to take one look and run away. So quality goes downhill, fewer new members arrive and the value of the franchise is reduced.
An alternative strategy might be to raise quality and delete about 8 handles. With a commitment to deleting any new handles as soon as the trolls reappear. In the short term, there might be a reduction in the number of posts, but in the long term it should work out.