It's a really hard one. They're both immensely strong ships and probably my favorite capital designs in the game currently.
Pegasus is incredibly strong. It also has a kind of an easygoing feel. I like the warm color. Of the two, Pegasus has a much lower skill floor and possibly also a lower cap. You can put any missiles you like on it or even roll a dice and so long as you put 4 facing-appropriate large missiles and and all the missile accessories on it you'll probably be pretty happy with its performance. An optimized loadout monofleet of 240 DP worth of Pegasus takes out 3 Ordos easily in terms of the damage they deal.
Executor is also incredibly strong. This ship by contrast is very harsh and unfriendly, so appropriate for Sindria. Even I thought it was bad for a while. It has a very high skill floor, due to the bad flux stats and using three different kind of weapons to deal damage (Ballistic, Energy, and Missile) if you misconfigure it - and that can be something as simple as even putting too many high flux guns on it or missing a maneuverability booster or not having enough caps - it'll be less than great or even terrible like the standard Gigacannon variant. However it also has a very high skill cap due to the excellent shield and the same three different kinds of weapon system. I've fought three Ordos with Paragons back when they cost 50 DP but I don't know of any other ships that use guns to deal most of their damage that could fight four normal sized Ordos at once in a 240 DP fleet. I'm fairly sure after reviewing that video that I posted that I can 1) defeat the final ships if I just give better endgame orders and 2) Defeat 5 Ordos too if I use one retreat so I don't run out of CR. We'll see.
Out of the two, I think Executor is my favorite even though it feels bad to say it because I also love the Pegasus and enjoy fielding it. Based on spending a lot of time fighting Remnants with both ships. Executor's strength is only shown in extreme circumstances though. If you are only fighting 1-2 Ordos Pegasus probably does it cleaner due to fighting from a distance rather than up close, 3 Ordos I think give the rebalanced Pegasus a harder time than the Executor because it is slow and vulnerable if caught by large Remnant ships and there's a risk of running out of missiles, 4 Ordos should not be possible for the Pegasus because it runs out of missiles.
By the way, here are the levels of Ordo fighting with 240 DP worth of ships that I use for reference here: 1 Ordo: any ship* including Ventures can do it so long as it's properly configured. 2 Ordo: good ships can do it when optimized. 3 Ordo: exceptional ships can do it, at least Pegasus, Gryphon in current version, probably also Conquest. 4 Ordo (aka the level the game won't normally even let you play with a 240 DP fleet unless you bring extra ships to trick it out of mercy mode): Executor and maybe Gryphon (haven't seen it, haven't tried it - Gryphon would not have a problem dealing the damage but might hit a PPT wall since my Executor runs out of PPT here even with Hardened Subsystems and Combat Endurance) I think. Happy to hear if you know more. These do not include the player as I never pilot a ship after early game, player can change things and increase fleet power considerably, and also by skill cap I refer to skill in building it for the AI and using it in a fleet. Plenty of good ships are twitchier in terms of player pilot skill.
*Within reason. The weakest ship I've used to repeatedly fight Ordos in a 240 DP fleet was 30 D-modded Condors in a Derelict Operations fleet. That was horrible and sketchy but winnable although also very losable. I think maybe a Prometheus (not Mk II) spam Derelict Operations fleet could win 1 Ordo. That's something I want to try but this 5 Executors vs 5 Ordo thing is the next project.
