[BloodyButcher]

The whole arguments is that stronger alliance will benefit from thsi than weaker alliances.
Maybe HRs defence peformance is doubled, and Ults only increased by a smaller margine, but the whole thing revolves around that from the new allie def fleet feature "stronger" alliance is able to use it better than "weaker" alliances and therefor increasing the gap even futher.
Why?
Defence/support planets is more common in say Ultores than say ND. With tags only counting for 40 planets, the bigger, and more organised tags is able to fill it up with defence planets wich tages basicly no effort to run.

Also the "bandwagon effect" of PA is DRAMATICLY increased by this new defence fleet feature(and offensive stats) as once the "pain barrier" is breach you would lose roids, and if it isnt breached no roids will be lost.
If say alliance A can cover 50 incs with 20 defence/support planets, no roids will be lost even without sending "real defence fleets".
If you want to breach the "pain barrier" for alliance A, maybe you need to send 100+ fleets, and very few, if any, alliance is able to do this.
So the only option would be to create a "block" or "bandwagon" as 1 on 1, and maybe even 2 vs 1 fights will result in no roid loss to either side.