Well, Sean Connery is (dashingly) Scottish. Liam Neeson is Irish, but playing a Scottsman (dashingly so). The hikers are probably Scottish, or at least in the UK from looking at the landscape, the couple is in formal attire (though her dress is a bit silly, the dude looks good), and that last dude is Swiss, but metal as fuck. (I would not mess with a metal dude in a kilt, would you?)
But yeah, none of them, minus the last one sort of, are mixing those with "contemporary" clothes, like t-shirts and sneakers. The hikers are wearing sweaters and both the hikers are the metal dude are wearing boots. You picked really good examples. It's the ones that wear kilts with casual, everyday things that don't look good. I mean, the dudes at the restaurant down the street from my store wear kilts with t-shirts, but they have on the socks and appropriate shoes, so they don't look as silly.