But Palpatine wasn’t born looking like that. His wrinkly face is a byproduct of him basically being a powerful conduit of the dark side for decades. So he became that way because of his long term use of the dark side.
So if these clones are just clones of the man Sheev Palpatine, then technically they should look more like regular Ian McDiarmid, and not the deformed Darth Sidious. But, like Faraday said, it is easier to quickly understand that it is Sidious because the clones look like how we recognize him the most. Also, you could kind of explain it away that perhaps these clones are a byproduct of both science and Sith alchemy. Perhaps they have to infuse these clones with the dark side in order for them to be even viable for his spirit. Could be the same reason Snoke is so fucked up. Creating dark side strandcasts leads to physical deformity, since it is perverse and unnatural.