Not sure how helpful this will be. However, FWIW, several years ago, I spent a couple hours critically listening to a MAC MA5200 and the Luxman in a head-to-head demo, using a Rega P3 equipped with an Ortofon Blue, Focal Aria 936 and a Rega Apollo CD player with well-engineered CD recordings and very good, very clean vinyl pressings. The CDs were my own; so, music I was very familiar with. Of course, this was a SS-to-SS shoot-out. What you have in mind is hybrid to SS, a different ballgame. My ears thought the MA5200 and the Luxman sounded virtually identical.
I've never spent any time with an MA252 and haven't spent much time with those Maggies. So, can't say what the A/B matchup you have in mind would be like. Going on specs, alone, I would say your ears will likely prefer the amp with the most robust power supply for those Maggies (i.e. not WATTS; power supply). Regardless, as with all things audiophile, let your ears be the judge.
BTW: Having critically listened to many MAC amps, over the years (more than Luxies); my ears would most definitely not agree that MAC's general sound signature is "very heavy (on) midrange and bass"; "rolled off in the upper treble range (veiling) upper-octave detail and the openness of the overall soundstage", that "Luxman ... has better dimensionality, textures and image specificity compared to comparably priced Mac(s)", that the "music would sound more dimensional with better instrumental/voice textures and imaging with the Luxman", that "Mac slightly lacks the last bits of details, resolution, texture and dimensionality in comparison to Luxman", that Luxman is "more musical and provided much more depth and detail than the McIntosh", etc.
I would agree, however, that this definitely depends upon the speakers used and likely would be a matter of preference, given equitably matched amps in a head-to-head shoot-out. Speakers are always the business end of any sound system.