Bi-amping question

Well after reading numerous articles on bi-amping, I still haven't figured this out. I have a pr of Totem Sttafs I'm running with a 15wpc tube amp. It would probably be better with more power and was thinking of adding an old Yamaha 50wpc receiver or even an old Realistic 25wpc receiver, with the tubes running the highs and the receiver running the bass. Some articles make this sound like a useable thing, others insist the amps have to be identical or damage can occur. Anyone have any practicle advise a neophyte could understand. I don't want to just try it and then have to replace damaged speakers. Thanks