Even PvE its possible- the problem is there are no NPC ships tough enough to close the gap and be a threat.They definitely would not be able to do it this efficiently if PPV2 was Open Only, which seems to have been the original intention by the look of this design.
Compare that to ATR- when they spawn in they are guns ready, and spawn in wings around you to form a cordon if you run.
You'd think the pride of a Powers navy would have spec ops level ships patrolling and scanning, and that quick response is by clouds and clouds of SLFs and more wings of spec ops set to a medium / high sec BGS time response (so from 30 seconds to 10 seconds).
That would be fun- especially in wings.
Back on another thread I suggested that this areas activities only counted in Open for power influence (but you kept the personal merit rewards).The easiest way to defend these stronghold systems would be if stronghold carrier instances were off-limits for NPCs.
The captain of the carrier should say something like 'sorry guys, you're too weak, stay away from this place'.