Would be really fun, although...
Why did you have such an idea? Do you not have enough PvP?
It's not about the bloodthirst
I was wondering how it would be to move the core action inside the bases (laying a siege, breaking a siege, etc.) since when they are unavailable for players of different factions.
Personally, I like the idea of such a event. Makes the war more... personnal. It gotta be balanced, through, so that one faction ins't overwhelmed in certain hours by another one. In american daylight, everyone would swarm family and BBs. During nights, on the other hands, fights would be fair. Maybe a player limit on each base-raid (20?) alongside constantly reinforcing guards?
That's an accurate point. The fight might be unbalanced as usual because of the daytime. Nevertheless, the limit of ~20 players would make the raid surprisingly easy to repulse in the time of increased activity of each faction.
I was thinking about the event idea a while and have got a couple of interesting insights/ideas:
a) the main base of competitive faction become visible if your faction controls two of the nearest control zones to the competitive faction gate entrance.
As all of you might have noticed, in faction bases you have to pass the gate in the courtyard to get to the structure - and what is crucial accordingly to the idea of EATG event, you can pass this gate only by going one by one (e.g. in BBoys or Family bases only one man can get into the structure at the same time). Taking that into consideration, the penetration of enemy base would be practically impossible. Therefore:
b) to be able to pass the entrance between the courtyard and the structure during the siege with more than one man, you have to control the enemy courtyard for at least (for instance) 15 minutes.
b*2) to be able to pass the entrance between the courtyard and the structure during the siege with more than one man, you have to detonate the gate/door with explosives.