Lappi and Mikkelsen are both WRC event winners and multiple podium scorers and are "active" (unlike say Meeke and partly Paddon). (The WRC part is important cause some drivers just don't adapt to the change to WRC well (Tidemand latest example)). So just picking someone good in Rally2 doesn't automatically mean he will do well in WRC.
If they are in a competitive car there is no reason they shouldn't be able to fight for podiums on most rallies. I'd say they are both roughly comparable to Evans and have proven so when in similar cars in the recent past.
It is easy to notice how Evans results changed when he moved to Toyota in 2020.
However, neither Lappi nor Mikkelsen are proven "top class" drivers like the WRC champions Ogier and Tanak, or Neuville who has many more event wins.
Evans kinda upgraded to this topclass after he moved to Toyota.
It is totally possible that some new drivers like Rovanpera, Solberg or Fourmaux will get to that top class level at some point. But right now not even Rovanpera can show results similar to Lappi or Mikkelsen (he has 2 podiums in 14 starts). Fourmaux and Solberg are another step down.
But in rally as in other sports, drivers often get hired due to "future potential", rather then "decent results" that you would expect from "old" drivers like Lappi and Mikkelsen.
I'd say a good team needs both "future potential" and older experienced drivers, but Malcolm has often picked just the new guys. Sometimes it turned out well relatively fast (Martin), sometimes it took long time and a few demotions from WRC (Tanak, Evans), sometimes it went bad one way or another (Duval, Camilli, could also rank Gardemeister and Kresta here).
