Heck, Tom Hardy didn't look that much like Patrick Stewart, even with the prosthetics they put on him and with the lines explaining how the shape of his face was changed by the beatings he got growing up. But ultimately their relative appearance didn't matter, because they were actors just pretending to be these characters, and part of being an audience is agreeing to play along with the pretense and suspend disbelief.
I didn't ever believe Hardy was Picard's clone.
He didn't look like him, act like him and was evil and have a lame excuse for being a clone. There was nothing to connect them, appearance was the least of my concerns.
Just as I never ever believed that Sybok was Spock's brother let alone a son of Sarek.
NuSpock and nuKirk don't really look like the originals but at least they try at some of the mannerisms. And basically they've got an excuse - its a reboot.
Most think Urban's an excellent McCoy but they have different eye colour and Urban is just gorgeous (no offense deForest Kelley but I have to give Urban the nod).