The Kronshtadt EBB is the only ship that has a gunset all it's own, the lvl 89 12" guns that the stalingrad had are what the EBB kron is supposed to use, it will not be able to mount any ammo with the 16" triples or at least it should not be able to.
It is a good improvement over the regular kron and out of the new EBB's it is the one i picked, it simply was not only wonderful looking but has great gun options that i simply wanted it.
Also the poltava can use the imp guns, it will be a bit slower than regular izmail but still it gets imp guns :P. You will still need to buy the stalingrad sorry to say but if you just use your kron to bb5 thats fine too, great EBB.