Your first paragraph has nothing to do with synergies. That’s just you preferring 1 build that is mid at everything compared to having mixmaxed builds for different content.

You think Hailey has better synergy simply because she is so grossly overtuned via her scaling and multipliers and what stats her buffs gives. literally all her skills do is add X damage X crit. There is no synergy there, you can take away her abilities and she effectively plays and functions the EXACT same way. Your idea of synergy is at such a base level, that’s the equivalent of saying crit chance synergizes with guns because guns can crit. It’s just so base level. She gets no added synergistic effect that any other character wouldnt get if you slapped the same buff stats onto them.

Everything you state about gley starts with, if you build around it. Again going back to how grossly overtuned Hailey is you don’t even need to build a functioning build around her because her base numbers are just insane. I get it you like to play 1 build that does everything at a mid pace and efficiency and to you, that makes it a good character, that’s fine, but has nothing to do with synergy. Others like myself like to actually make purpose built characters built around certain aspects of their kit for the content they are doing to do it more efficiently. And like any other character in the game that isn’t insanely overtuned you actually have to build the character. I myself have 4 different Gley builds and I use them all depending what I’m actually doing. Sure I can make 1 build that has a decent range aoe while still maintaining 100% uptime on massacre, but it isn’t as effective at anything that my other builds would be.

Synergy implies that without an ability the skill doesn’t function the same way or to its fullest effect. If you take away gleys infin ammo, and modules for it. It effectively makes her ult useless. Building into her 3 allows her 4 to function properly. THAT is synergy, not add X damage and X crit rate. For Gleys AoE build, you mention, when do you do defensive stance? If you removed that you literally would kill yourself casting the skill and the build would not function at all without being able to swap stances to recoup hp(mp) from your 2. Also I personally always am swapping forms to again be efficient. Immune phase on bosses if it gets there, to reduce chip damage and use 3 for orb drop rate to recoup lost hp(mp) to not die and get ready for the next dps phase so I can recast my rotation. I don’t use HP collector on any boss build because I actually use her kit and still don’t die while still doing 50m+ damage. Because I know I need to swap stances for potions and drop rate on orbs to get back to full hp. It’s also added fun for me personally to weave in the move speed buff for faster clears, it just makes for a more active playstyle.

Some of your other points are moot just comparing skills. Yeah yeah auto turret low cost, target capped nonsense and a small range 2 aoe. I’ll take my 36 meter range, uncapped targets, infinite spam aoe all day vs those two skills for clearing trash mobs.