Ok Gentu has said that he will help out with the base so hopefully it'll go a bit quicker. The idea I have for it, is for it to be a single giant tower. The 3 bases would be located within the tower on different levels, and ideally you will be able to go on ledges/ walkways on the outside of the tower to then use ladders which will act as additional entrances to the bases.

So basically the tower would act as 1 giant base, with the 3 individual bases sectioned off within it. So hopefully whilst you are fighting in 1 of the bases, you might see other players who are attacking other bases on the ledges above you (will make sure they are far enough that you can't damage eachother