I don't have any answers. Sometimes, the similarity is obvious. Other times, it's a stretch. If it's obvious, I'll fix the painting. If it's a stretch - I may not.
On Campobello Island, there's a rock outcrop just off shore that is charted as Sugar Loaf Rock. The locals, however, call it the Frog Rock. It's pretty obvious, but you might not think it, if someone didn't say it. I paint that rock a lot, and now I have to work hard at cosmetic surgery to minimize the rock's frogginess. (I can't help but see the frog.)
You'll go insane if you look at your paintings and try to discover all the faces in them in an effort to avoid them. Sure, avoid anything that's obvious. And don't paint a cloud because it looks like Uncle Bob. Paint the cloud because it supports the idea of your painting.
My advice is - don't worry about the faces. Just make a good painting.
Here are two pastels I did recently, neither of which has any faces, as far as I can tell. They are sketches done on a material that's new for me, PastelMat. I like the way it holds pastel.
"Sail Rock" sketch - 3x6, pastel, $60 - buy
"Uptown Trails" sketch - 3x6, pastel, $60 - buy