Set Consistency

[vintagebaseballcardguy]

I am finishing at '53 Topps set...again. I have a little start on '54 Topps and might come back to it. Next up, I am really thinking of '56 or '57 Topps because I think I could build a little higher grade of a set. With that said, I have learned a lot about consistency within a set. No matter which set I go after, the cards will all fall in the same range on qualities such as centering, registry, focus, etc. I expect the set will be a graded one. What do you think about a set that is largely graded in the 7 to 8 range (and high end examples of those grades) but the Mantle, which usually ends up being the most expensive card, coming in in the 6 range?? This Mantle graded a 6 would possess the qualities of the 7s and 8s in terms of centering, etc., but it would be a 6 while most of the rest of the set would be 7s or 8s. Would this look odd? I try not to get too hung up on what the holder says, it is more about eye appeal for me. I buy the card, not the holder. Would buying a Mantle a notch below the other cards look cheap?