Just took this screen shot moments ago:

Rooks lost more than half their fields and Bish/Nit combined lost one single field.  43 players vs 5 on two fronts.  This is your three sided arena balance.
One country gets tag teamed like Poland in 1939, because it is easy to have double the numbers (or a shipload more in this case) and steamroll bases.
But this is bad for the game.  People logged out, including me.  It's time for a rule to prevent this.
Make a limit on % of bases that you can have on one country vs the other.  Specifically, Country A can't take more than 10% of Country B than Country C.  Once Country A has 10% of B, they must take from Country C before nay more captures from B.
People love easy mode.  That will never change.  But you can't let this dogpiling go on without limits.