Truth be told, I dont think Lucas is 65:35 against MK either.
Its probably worse.
I think this purely on a trait/ability criteria in comparison to the things MK has shown to be weak by.
Literally:
Out ranging an MK disjoint
Having move(s) which out range Meta Knight
High Priority fastish move (cool down/start up)
Strong mobility
I dont think Lucas has any of those things.
Take at Wario.
His ftilt is slow start up, but outranges MKs disjoints, its SILLY, but it actually is HELPFUL in the match up for punishing bad spacing (and remember, if a character actually does not have the means of punishing MKs bad spacing, I wouldnt call the MU winnable). Warios uair outranges the disjoint on MKs dair (its still hard to beat it though).. Not saying that these automaticly make Wario WIN/GO EVEN but HAVING THEM HELPS. I do NOT think Lucas has anything like this. His utilt and upsmash sure... Maybe his fair?
Out ranging MK? Well.. Wario doesnt do that... and there arent many characters who do... Theres like Snake (2nd hit ftilt), Falco (fsmash), Diddy (fair), Marth, Dedede (ftilt), Olimar (grabs), Lucario, Link... Poor Lucas
Wario isnt a prime example, but he has things. His Aerial Mobility + Jumping ability + some of his aerials combined result in GREAT FASTS priority. His fsmash has super armor and fast start up, SUPER ARMOR = win as transcended priority naturally loses to it (if you havent noticed, Super Armor still clashes with normal moves). Falco and Diddy are the strong points here; Lasers and Bananas.
Strong mobility? Warios got this in terms of the air. Lucas isnt too bad in this IIRC as well. How does mobility help? well in most cases these days, mobility helps in running away, or being able to cover the distance of MKs whiffs. I dont think Lucas is able to use his mobility to punish whiffs too often, MKs size + low cooldown in general + taking into consideration how hard Wario struggles getting in through the air whilst Lucas has weaker ability in this regard (and I dont think his ground mobility covers it).
Theres other things that MK has ... issues in.. But all I see Lucas has in the match up is reasonable kill power and okay-ish start up on some of his moves. I cant think of Lucas being 60:40, let alone 65:35 when you have to include that MKs dash grab outranges and outspeeds Lucas aerial cooldown/lag and whiffs on his moves, and that Lucas getting grabbed = serious amounts of pain.