Well.... On paper and at face value, yes, those statements are true. However, I would say that strength of schedule has taken a significant dip since the end of the WCHA 1.0 in 2013. In my opinion, playing in the WCHA 2.0 and CCHA 2.0 is worth about 4 more wins per season on Tech's record, regardless of who is coaching the team. The collective strength/quality of our conference since 2013 does not come anywhere close to pre-2013.
If you back out four wins per season that Tech played in those two conference arrangements, Mel drops to 110-100-29 (0.524 win percentage) and Joe drops to 85-77-16 (0.525 win percentage). For comparison, Mike Hastings record at Mankato since 2013 playing the same conference teams (and arguably a harder out of conference schedule most seasons) is 250-82-21 (0.753 win percentage).
Also keep in mind Mel/Joe are the only two coaches that even have winning records since John. So being one of the best since John isn't setting the bar super high.