what's in a name?

So my fiancé and I are not waiting to have kids. We each have our own. He has two girls and I have a boy. Before I met him I fell in love with the name Greyson for a boy. Turns out his oldest' name is Gracelyn. 😩
We are both hoping for a boy but I just can't decide on a name. I keep going back to Greyson. ❤️❤️❤️
Would it be too weird? Their names sound practically identical and besides, I don't want his ex to think we weren't creative enough to find something on our own. Ya know? 
What do y'all think?