but i didnt say pokemon mystery dungeon, i say pokemon stars, as in new mainline entry
no its like saying nintendo does not release Return of Samus at the same time as Metroid Prime 4. Which, what suprise, nintendo doesnt
I said that spacing the release would be better. Ideally, MHXX would be holidays and MHW in March of whatever date Capcom is planning in 2018.
Also, we are under the assumption that MHW is the next big thing in Monster Hunter and wouldn't fall short when compared to XX, as it is an old gen game. In fact, we should expect World to be a significantly more compelling product, which is a very different situation than the scenario you posted.
On my scenario, Capcom get more money from MH core fans, as they buy 2 games instead of 1. From Switch only owners that are interested in the franchise and Switch owners that are new to the franchise and get the only big third party game available for the holidays. They might even like the game enough to be compelled to buy World! Then, they get all the sales they were planning to get with world in march.
As in Nintendo example, Return of Samus is designed to increased the interest in Metroid, not to lessen it.