I think you used the right word here: Synergy. I used to suggest always buffing a character’s strengths, but as I’ve become more experienced I’ve realised that gear choices really depend on the character, the build you use, and your playstyle, even map and mode come into play. For example, I typically run a wrench on Outskirts, but not Paradise or Coldsnap, and again on Overgrowth but not Echelon or Monuments.
Playing to a character’s strengths vs playing to their weaknesses really depends on the character in question. For example, Orendi has bugger all health BUT she’s bouncy as hell and has a very small hitbox, if you’re mobile enough you can barely get hit so health stacking is not necessary. Her strength is obviously skill damage, and if you stack skill damage you what happens at level 10… In Orendi’s case, I build her specifically for Pillarstorm every match because I don’t ever intend to not hit level 10 with her, and even when a match doesn’t last that long I still have maximum skill damage to ensure that minion waves don’t exist and any interfering Battleborn will feel the full force of a max damage Shadowfire Pillar.
Phoebe’s an opposite example. She’s an melee assassin/brawler and naturally when she’s landing hits she’s getting hit back by something, so instead of boosting damage we want to make sure she can survive close-range encounters because getting a kill means nothing if you die to secure it. Health regen and max health are always important on melee characters who can’t possibly avoid taking some damage, and in Phoebe’s case her biggest weakness is her slow speed. I sometimes run movement speed and sprint speed gear on her, or health regen and one of those two, so she can keep up a chase and make a hasty retreat while the regen keeps me from having to run back to supply stations or teleport to base every time I’e been scratched.
Two completely different characters, but one I gear toward strengths while the other I gear toward weaknesses. There’s no right or wrong way to do it. Except for health stacking Orendi, don’t do that.