Luigi Mansion 3 is performing really well across the globe and the momentum is holding steadily for this month too. It's safe to say LM3 is this year's Super Mario Party with an exception to Japan where SMP smokes LM3 really badly in aligned numbers.
MM2, on the other hand, is performing below my expectation, I guess NSMBUD really did affect MM2 performances since both of them were released in the same year. NSMBUD should've been released in 2018 to build the anticipation of the new MM2 especially when how barren the line up of 2018 for Nintendo Switch.
It's not as bad as you think if you consider that SMM2 has been in and out of stock on Amazon since Black Friday. I know every time I checked the yearly chart, SMM2 was always being sold 2nd hand.