Kubalik never would commit to the Kings and wouldn't even come to camps, so how could the Kings do anything with him, let alone pair him with someone? He showed zero interest. That move had everything to do with Kubalik and nothing to do with the Kings.
Necas will be solid, but a #1? He's never shown anything close to that kind of ability. #1 guys come in and dominate at a young age, like Kopitar, McDavid, Towes, etc. His ceiling is a 2/3, which isn't bad at all, but he's never shown top line chops.