LeM would be the more ‘child-friendly’ choice. If you can apply SNAs to a booking then even the most commonly given suite is very large, plenty big enough to accommodate roll-aways. The risk though is that you might not find out about the success or otherwise of the SNA application for a long time.
Also, the bathrooms at the LeM are more suitable: the suites have a large bathroom with stand alone tub that young ones might find appealing ( at least up to that age when they decide any bath is to be resisted).
Lots of families use LeM and it would be a practical choice.