the main thing and most important thing is that you don't have the space for an VLS next to the funnel due to you'r engine room and other things like... top heavy.
to fit an VLS:
1. need space for it, a lot of it.
2. the deck the VLS is standing on must be reinforced, depending on the size of an VLS: an reinforced deck can take up from 10% of the deck space (in height) to close to 50% of it.
3. Then you need heat protection, that will take some space to.
4. then you need space for the engines, and they need a lot of space. It's not like an engine in a car. Her you can walk around it, over it and some time under it.
I would say that you can calculate that there will go approx 1 deck or less just for reinforcing and heat protection under the VLS. the VLS need approx (depending how it's mounted and what type of Mk41-VLS) 2 and a half to 3 deck height. the engine room needs form 2 deck to 4 deck or more of space. that give us approx: 7-8 deck. then you need to add in the keel and the space around it. that is another deck to the list.
This is the size of an Mk-41 VLS. bigger than you think: