Take the Juneau II,it has 5 support slots (CA/bb1 support slot size) which is very nice for a CL. It allows you to level more sailors, and you have more SD (Message me if u wanna know what SD is) and you have (probaly) more speed.

Thats not true.

It has 5 support slot, but lost the 2 T slots on the ship, so the total number of sailors leveling is the same as an oakland or atlanta.

As far as SD goes, whatever the position on the ship, the sailor gives a fixed ammount based on its restore true ability. Even gunners, abeit a really small ammount obviously.

The only thing support slot vs ship slot has an impact on is some classes. Namely, engineer, pilots, medic, and I think seaman but I won't go there as I'm not sure how they work.

The atlanta-class CLs don't have plane space, so pilot don't need to be on a support slot,

So the advantage of the support slot is limited to :

You can run 5 engies or 4 engies with a medic with their ability working, compared to only 3 engineer or 2 engies and 1 medic.

Unless you really absolutely want to run with working 5 engies (most dont care about medic at that point, and I'm pretty sure they fixed cv loss enough so they dont care anymore either. Would need a cv player to confirm tough) There isnt much point to choose Juneau over Oakland.

Or stay with atlanta and saving the remod cost as a new player.

You can still level 5 engies with those, even if two are really taking a break and only pumping additionnal SD without affecting your OH speeds and time.