Let's pretend this is true for a moment. These five potential acquisition targets are very different companies, with some being in much better financial health than others (and thus easier to buy).
Rare is obviously owned by Nintendo's competitor, so it can't possibly be on the list, unless Microsoft is planning to disband their Xbox division and forgot to tell everyone.
Sega has been doing poorly for over a decade and would make an attractive purchase for the strength of its back catalog alone. Not sure how much development talent there's actually left at Sega in Japan today, and of course there's Sammy's pachinko business that Nintendo probably couldn't care less about.
Capcom and Konami would be a Nintendo fan's wet dream. Rumors and/or wishful thinking about Nintendo buying either one of them have been around since the "megaton" days, but none of that ever came to fruition.
Namco-Bandai I don't know. Not sure who the heck needs them, and they wouldn't be cheap anyway.
For what it's worth, Nintendo has stated in the past that they are not very acquisition-minded when it comes to buying out competitors. But they do seem to lack the development resources to churn out AAA first-party titles like they used to and may perhaps benefit from a talent infusion.
