Give them transferable tag....but for everyone they get they must allow 10 hunting days to the general public. A list of cow only tag holders and the hunter is pulled from that list. Hunter #1 shoots a cow first day....9 days remaining. Next hunter comes in and kill cow after 2 days. 7 days remaining etc. Or they can have 2 hunters per day for 5 days...etc.
Most landowners know enough people or have enough family and friends that would gladly come shoot a cow it is really a non issue. Also, why the hell would an outfitter or even the land owner demand the outfitter remove X amount of animals a year. Put it in the contract. For every x number of bulls an outfitter and their clients take they must harvest Y number of cows. OR...Outfitter must remove X number of cows BEFORE your clients can harvest a bull.
Landowners do not want to actually solve the problem plain and simple.