Jinrokh, pool is pretty much a must. I'd argue this is the less costrictive positioning mechanic in the entire raid tier.
Horridon, on basically every door you want ranged to be between the tank and the door which is going to activate next, so that the tank doesn't have to run around like a headless chicken trying to get everything.
Council, pretty strict positioning for priestess adds on heroic, kazrajin discharge, frostbites, all with sandtraps thrown into the mix.
Tortos, avoiding turtles while at the same time being roughly everyone on the same side before each quake stomp.
Megaera, staying in precise positions to efficiently kite Torrent of Ice
Jikun, stay loosely spread around the border in order not to chain caw with someone else/melee, while paying attention to downdraft (less gap closers/sprints than melee)
Durumu, beams, walls and maze pretty much say where you have to stand.
Primordius, stay spread for pustules/acidic spines
Dark animus, stay spread in order to avoid linking golems, pay attention not to be one of the most external people if you aren't soaking matter swap, while anima fonts mess up everything
Qon, stay spread in order not to chain arcing lightning
Twins, spread for cosmic barrage during night and for light of day during day. Spores are much more frequent in ranged too.
Lei shen, precise positioning for ball lightnings, precise positioning for thunderstruck, precise positioning for diffusion chain during normal phases, precise positioning for bouncing balls soaking whenever they're cast.
Ra'den, whatever, it's the same for both melee and ranged.
While this is spoken from a 25hc point of view, where spreading actually has a huge impact compared to 10hc, I really can't see where you're coming from with your assumption. Strict positioning is pretty often required, it's not just a "stand wherever you want to stand". Unless you're overgearing content or doing easy content, of course, but does that really matter?