Okay, so in order to own a base I need to pay money, and now pay more money for mercs, and level up another slaver alt in order to have a decent number of mercs/slaves there (5 per alt).
Even more alts would be required for protecting a base post-wipe, since it will be less mercs per character (at least less powerful ones, depending on what the limits are post-wipe). The point is that it will just be another alt to protect your base.
The people that have mercs would just farm other players that drop into their base by having them insta-killed by mercs.
And the owner wouldn't even need to be online - just sleep in the night, log-in the next afternoon to see how many players have succumbed to the mercs, collect loot.