This is enough

Not really, OH speed and time is greatly reduced as is repair rate.

The Stalingrad has very good and a lot of T-slots, don't knock it for AA.
As for it being fragile, so are a lot of other BB4.
Krohnstadt AA is decent as well.

If your want a complete crew: 4 gunners, 6 engineers, 4 repairers  and 1 or 2 scouts gives you maximum flexibility. With such an amount of crew to level, 2 BO are almost required though.

If you'd like a change of pace for significantly faster reload with lower range and damage try the minizinis. a bit less range, still kills stuff, but way faster reload at 1.56 vs 2.76. Just worth a try. 

Having played SN to 120 (and even though this thread is a month old) for everyone else I recommend:

1 BO (premium ships help keeping levels more balanced but they're not necessary)
2 Main Gunners (BVE 11/11 do quite nicely, really)
2 AA Gunners (Soviet has very usable AA if you don't at least want HH)
4 Reps
4 Engies
1 Scout 

Yeah, if you'd like to work towards a P24 you can't possibly use, go with Toryu's plan :\. Why of all things you would waste your time grinding for the purpose of only ever getting to BB5 for SN of all nations? :S madness. SN BB5 is terrible. BB3 and BB4 are golden gods of awesomeness. Don't take twice as long to do a grind that only gets you to BB5. You'd be better off spending slighly longer grinding on a BB4/BB5 than doing it all twice. That's just math right there. I suggest either use a PCA/PBB/PCV/whatever to help, or even if your BO is 110 and you still need to use the Stalin to keep your supports at ship level, it's still faster and better than doing it all twice. (just think of your BOs level as only being what your supports levels are, to keep it simple). I think it's ridiculous when anyone uses two BOs for this reason.

Basically,
don't give advice that leaves people screwed at 120. That's like saying "Oh only bother with AA gunners cuz eventually the BBs get stupid. Just stick to AA for this whole nation and never bother with BBs" if you're telling someone not to work towards their BB6. Especially with SNs BB5.


Anyways, I myself went 5 engies/3 reps and wish I went 4/4. It is very easy to hit speed cap at level if you're boosting even +11 Engies (though remember, SN plays a lot like KM. OH is your friend :D). That being said I've also got way more OH than even SN needs. Also I know my Rep rate should be higher. All this leads me to conclude that my P24 should have a 4/4 split for supports. As soon as you start using terms like "working towards flexibility" you're essentially taking away from what your ship should be doing best. "A jack of all trades is a master of none".