No, these have been bases reappearing in roughly the same area. They are in an area where I have other base areas overlapping it, but I have only been active in the area of one base for the last few weeks. The FoT bases aren't just for me, though - are they? Could they be for other players? I don't have any other players active in my area that I know about, though.
Ah, that explains it. I hadn't noticed that before. I had noticed the cooldown on construction had sped up significantly.
That's not what I meant. I was able to initiate an attack against FoT while I was still being attacked by it. Previously, it would say "your base is already involved in combat" or something like that. That said, when I tried to repeat it a little while later, I did get that message. So, perhaps it was a timing issue.