While i think that could be fun, it will has it own problems. Basically any pillar base will be very very hard to raid, and if activly defended it might even be impossible if the defender has the resources. Another point is that underwater bases are impossible to raid, simply not being able to dmg the turrets/plant x before they shoot you (grenades cant be thrown out of water and fire arrows dont work underwater, duh). Autoturret would need to be disabled because it would be impossible to raid certain spots even with a cannon. I know getting a good and balanced pvp server is hard but if we all think about it together we can make it possible .

What might be a good solution would be to decrease the amount of dinos one tribe can have, to a number like 50 (can of course get changed to be higher or lower, but rather lower). If you decrease the amount of dinos a tribe can have, you decrease its power pretty hard. Suddenly they cant breed and tame anything they want, they need to think on what they should focus, what they dont need and how many of the dinos should be just breeders. This would make it possible to give smaller tribes a fighting chance.
Cryo fridges would have to be disabled and if possible cryopods should have their expire date changed to 12h or less, so nobody can just collect an incredible amount of dinos exceeding the limit by far.
Bosses should be a lot easier on the PvP server so smaller tribes get faster/can get tek, even beta dragon on the pve server is with my current line up almost impossible, beat it 10 sec with my shotgun after my last theri died and it chasing me.
Cannon should be disabled because i feel thats a very boring and cheesy way to raid people offline, its more popular the higher the gathering is.
Maybe throw a offline raid protection system in, it certainly is popular on the MTS-servers (most popular server cluser since a round a year i think?), doesnt seem to make the server lag or anything anymore.

That was just a suggestion for the start, reply what you think about.