Hello!

We are redoing our bathroom and we wanted to add wainscoting picture frames to our bottom half of our bathroom. I bought some premade 16x20" https://www.homedepot.com/p/Ekena-Millwork-16-in-W-x-20-in-H-x-1-2-in-P-Ashford-Molded-Classic-Wainscot-Wall-Panel-PNL16X20AS-01/205755197 to make this job go faster. The only issue I'm seeing is I have to deal with 4 different sized walls in my bathroom.

The largest wall is 70." The wall that shares the largest part of the vanity is cut down to 32" The smallest wall is 18" (shares with Vanity) and the other is 27 1/2" (Shares with shower). How do I do the picture frames the same size and maintain a great look? It seems like there is no way to maintain the correct spacing as well as the same size of the picture frames. Any insight would be highly appreciated!