Another approach than single-ingress/multi-ingress is having a multi-stage ingress, possibly with the opening stage being multiple planets wide, but to actually hit your core the enemy has to funnel through a single system.
This doesn't seem to be very popular but I'm not entirely sure why; it seems like simply introducing more temporal spacing between the elements of a wave (as happens simply from movement, let alone engaging stuff along the way) would make the whipping boy defenses more effective at least in avoiding econ damage.
<snip>Edit: Oh, yeah, to boot the wave that hit your outer layer, the ones that want to keep going for the homeworld, will usually stagnate as threat and never hit the next 'layer', making the attempt moot. All you did was create a neutral system until your fleet can come clean out the problem.
This is the biggest problem with multi-layer defenses. I sometimes even see parts of Exowaves stall out and sit as threat rather than suicide against strong defenses. Unless wave units are forced to be suicidal.
<snip>
The AIP effect on wave strength is now (AIP * 0.
^ 1.1. This basically means a 50 point AIP increase results in a 57 effective AIP increase for wave size. A 100 point increase in actual AIP gives a wave-effective 123 point increase.
But effective AIP is only one factor in wave strength. Difficulty is huge (2.25 multiplier at diff 7, 2.5 at diff 9; at diff 10, this is 4.5). Wave interval is another big factor, since at max interval this is about 2.0 multiplier (can be 2.26 or so with 1 ingress). Even if you only go with average, the 6+ ingress multiplier still averages about 1.2 - 60% of the 1 ingress average.
There are a lot of other factors in wave strength, so I'm not sure if even these multiplier get drowned out (or enhanced?) by other things... but I'm pretty sure I'm close.
Basically, going from 50 AIP to 100 AIP by gate raiding 10 warp gates gives about a 115% increase is wave strength due to AIP, plus a 50% increase due to going from 6+ ingress to 1 ingress. Multiplicitave, not additive, gives an increase in strength of +175% or so. Aka, almost triple what the average wave would have been against one of 6+ ingress points.
However, 6 ingress points gives your fixed defenses a mere 16.67% strength per system. Concentrating that gives a 500% increase - Aka, it's a better improvement than the increase in AI wave strength. When you do the math based on MAX wave size, not average, the ratio gets even more in favor of the whipping boy.
Finally, in regards to turrets vs fleetships.
Mk II basic turrets have 300,000 cap-DPS and 30,000,000 cap health (or so).
Mk II fighters have 200,000 cap-DPS and 32,000,000 cap health.
Mk II Missile Frigates are 170,000 cap-DPS, 30,000,000 cap HP.
Mk II bombers: 140,000 cap-DPS, 30,000,000 cap HP.
The other turrets have even better stats (HBCs, for example). Sure, they can't go on the attack - but for the price of a single Mk III fleetship unlock, you can unlock 2-3 Mk II turrets.
So, unlocking a few turrets until your whipping boy can stand alone
is Knowledge efficient.
When surviving is your primary concern, turrets are better. Period.
In the situation where you can:
1) control threat, and
2) survive,
then you have a chance of eventually
3) using your fleet to wear down the AI and win.