That sounds like it'll be a fantastic looking setup when they all get into the 240. Good luck on the L191 royal's growth rate - it's slow. I had mine from about 2" and it grew to about 7-8" in a little over 3 years. Not a very fast growing pleco, but it is absolutely stunning when they get bigger. The color is unlike most others. Yours still has the white on the tail, which will completely disappear as he grows.
Here's mine at maybe 3" and then again around 7":

Here's mine at maybe 3" and then again around 7":



