My solution which everyone will hate is to do like Pride. They tell you you're going to fight like a month or less in advance and you find out who your opponent is a few days before when you get there. Does away with two things 1) cycling (needles, not wheels) and 2) excessive gameplanning (guys will just have to train for everything or specialize, their choice). I think number 2 will lead to way more finishes because guys are spending half their camp on neutralizing their opponents biggest weapons.
The #1 and #2 matches on the card could still be announced as normal. This would be required to promote the card. No one is flying out to vegas or pay for tickets otherwise. You then do random drug testing for those guys. Their revenue warrants the cost and it removes the complaint Zuffa has about the excessive costs and crazy logistics of random testing their whole roster (and they are right). Also one would assume that if they got through climbing the ranks on short notice fights without getting pinched, then they are very probably clean.
Guys could be allowed to opt out of being on the roster and remain on contract. Could be for injury, personal reasons or just not wanting a fight. But if you put yourself on the roster and you're not at or near the top in your division, then expect a call anytime.
"I chose to do this sport and now I choose not too. Mentally, it's a lot of pressure. No one can understand it but me." - @GeorgesStPierre