5 cartridges - Cello, vdH, Benz, Zu, Hana - what stays and what goes?

If you've got two very nice turntables and 5 cartridges, it behooves you to master the art of cartridge mounting.  Like MC says, it's not rocket science.  And if you don't do a perfect job, so what?  Many who think they do a perfect job probably don't, so you're in good company. The more you do it, the better you will be at doing it.  If you want to be as nutty as the rest of us, you need to be mounting your own cartridges for yourself.  MC is also correct, or at least I agree, when he says that hearing how two different cartridges sound in your own system, where you can go back and forth among several is per se very educational and gets you down the path of finding your own personal nirvana quite a bit faster than otherwise.

Learn how to mount a cartridge for yourself and keep them all until you have had ample time to evaluate each one in your particular system.  At that point, you may want to sell one or two, but the decision will be wholly yours. Or maybe instead of ditching a cartridge or two, you ought to consider mounting a second tonearm, if your turntable permits.