Sarcy,
With regards def leppard, Rick Savage plays bass by the way Rick Allen drums. Most of Hysteria album was bass samples and sequencers, I have tried to play gods of war bass line, and can play it pretty well, but never going to get it right as it's a synth bass and absolute no string noise what so ever, still a great bass line. Pretty much all other def leppard albums all bass is real. And certainly is live.
love kiss but yeah pretty much apart from early stuff don't reckon too much bass in studio is Gene Simmons.