Having Beck/Kapanen or Evans on the 4th line isn't going to make much of a difference to the habs making the playoffs. The impact of a 4th line center is limited.
RHP is a small winger drafted in the 7th round as an overager and is now 25 years old. Beck and Kapanen are both good-sized 2-way centers who are great on faceoffs and were drafted in the 2nd round. The pedigree/value of RHP and Beck/Kapanen are nowhere near the same.
Beck and Kapanen don't need to be a perfect 3C/4C to be in the NHL. They will be rookies, so there will be ups and downs. Slafkovsky, Xhekaj, Roy, etc. weren't perfect players when they made the nhl.
We're not going to run Reinbacher Mailloux Barron on the right side because one of Guhle or Matheson will be on the right side.
Guhle - Matheson
Hutson - Reinbacher
Xhekaj - Mailloux
Reinbacher, Mailloux, Engstrom, Trudeau, Struble, and Barron are all knocking on the door, and Savard will be blocking one of them, and probably won't even be better.
They aren't going to sign old players who will block prospects from making the team. That's pretty clear with what Hughes has been saying to the media.
There is also already veteran depth players signed for multiple more years on the team in Anderson and Gallagher.