That said, I'm assuming the separate values weren't just introduced on a whim. Alex, I'd be interested in hearing what the original rationale was? Then we can talk about whether the good outweighs the bad.
Yeah, from what I recall, I didn't particularly
want to do this, but it seemed necessary, or at least the simplest course of action. Couple of assorted points:
It's useful to decouple supply/deployment point cost from autoresolve strength. One key example where this comes in handy is stations; star fortresses top out at 400 fleet points.
A less prominent example is that self-same Paragon. Of course the FP value is abstracted, and 3 Hammerheads generally lose to a Paragon, but in terms of overall strength in various scenarios and not head-to-head, this isn't as unreasonable. Plus, more importantly - this strength is used for fleet engagement decisions. Should a fleet with 3 Hammerheads want to engage a player fleet with a Paragon? I'd say definitely yes; while a fight with those odds is player-tilted, it's also in the "likely interesting" category. And, well, one could always bump up the FP value of the Paragon, if 30 felt like it was too low. So the way fleet points are tuned, the AI is a little more aggressive. That could be handled separately, though.
Basically every complaint involving capital bloat in things like expedition fleets and similar mod content. In particular, I believe the FP/DP mismatch is partly responsible for that annoying difficulty spike where e.g. a 150k named bounty can have one capital, but a 300k bounty has like six.
This is really more of a fleet creation issue, imo. The logic there is intended to get certain results and while fleet points can affect the outcome, so can changing the code. To wit: high-end fleets look significantly different in dev already.
Basically, these just don't quite do the same things. Deployment points are a bit higher for large ships since they feel like they ought to be more expensive to deploy given just how much the player can get out of them. Fleet points are a bit lower. Except when they're sky-high, as for stations.
Honestly, I could see generally making FP the same as deployment points, with some exceptions - but this would be a pain in terms of changing stuff that works off the current FP values (such as bounties, salvage, fleet AI, fleet creation, etc). And it doesn't seem like an improvement, but more of a lateral change in terms of where the special cases go.
I don't think the downsides are really downsides of fleet points being separate, aside from "more complicated for modders". But even there, it's useful to have these as a level for producing desired fleet compositions without also affecting the player-facing supply costs.