I think the lag there is from something that Chris is investigating right now, of which Marauders fall victim to.
For your strength - 100 is extremely low at that point. I think that kind of low AIP style is still very viable currently, due to the addition of the Major Data Centers (when held, AIP reduced by 60. Goes up by 90 on destruction). It's actually been a thorn for Difficulty 10, how much reduction there is. You can capture more planets here while keeping it really low.
Looking around in the save, there's a lot of stuff untapped. You don't have any Major Data Centers, each of which would allow you to capture 2 planets beyond the one it's on while keeping AIP the same, and a lot of unused Hacking Points. A lot more of your power comes from Hacking here, as a major part of it are things like Advanced Research Stations, Tech Vaults and Fleet Capacity Extenders. There's also the Intra-Galactic Coordinators, one for Strikecraft (the Fleetship replacement), Frigates (Starships) and Turrets, which increase the cap of those things by 30%, after everything else.
So from the position in your save, you could capture a few Major Data Centers and get a lot of reduction, Hack a bunch of ARS to fill up some more Fleets, use some Fleet Capacity Extenders to get more of the things you like/want/need, get a Tech Vault or two for those units, then capture an Intra-Galactic Coordinator to boost it even further. Then destroy some Distribution Nodes to get more Science and Hacking to boost them more after, all with only a little AIP increase.
Hope some of that's helpful. The Overlord is...maybe a big spike for that difficulty compared to the normal defenses, but someone else with more programmer ability would have to change that. For the higher difficulties it's a bit of a pushover relative to the planets.