Look weird? *shrug* Perhaps, but aesthetics are your call lol
However - while testing a build, I very recently ran a semislick rear tire w/a knobby in the front & I can tell ya this... running such mismatched tires leaves you with the worst of both worlds w/the knobby plowing turns on pavement & the slick slipping on grass & dirt etc. Ya jus' can't win.
I ran 'em for a few days while I waited for my new tires to arrive, I kept thinking I'd get used to the odd handling... but I never did. It's a really
really weird ride and I don't recommend it if you've any choice.
I mean, obv it's not the end of the world or anything lol it's just freaky and I don't like "freaky" when it comes to traction & handling, partic in turns