+1 on the randal for the size. Mine came tiny and I was a bit concerned with pairing with the YWG that was multiple his size, but they paired just fine. the randal also doesn't seem to be a faster grower which is actually a plus in my tank (65g). They've been together for about 4 yrs now through 3 tank changes. I'm one of the lucky ones where the burrow is front and center where I can see them all the time. Mine hasn't been destructive in any sense with stealing frags/coral. They just tend to move sand around and I'll occasionally collapse the tunnel just to keep them busy in rebuilding. Wife says it's mean, but I'm giving it purpose . lol.
One thing that I found interesting is that I never saw the YWG eat anything for probably first year+. Enough that I had to research to see what the heck it was eating since it apparently gets enough to live. Was't until I started feeding tank frozen that I saw it eat. Wouldn't say it competes for food..lazy fish. Just hangs out as the optimistic eater.
Good pair! I also have mandrin, firefish and tailspot 8 others species in the same tank. zero aggression everyone just gets along. I named those since they are similar and I've heard of aggression but no issues for me.