As it turned out, since I'd moved the neons and lone rasbora out to another tank, I had room for a couple more clowns that stole my heart at the LFS. They are now out of QT, and swimming with their new family in the big tank with the 3 other CLs, few blackskirt tetras and glasscats- and of course, my monster pleco, Ralph, who before now was pretty much king of the tank. Not so anymore!
The 2 large (3-1/2") and 3 small (about 1 to 1-1/2") are getting along famously. They are all over the tank- either all together or in smaller packs. Even the larger, established ones are eating better and more often. And Ralph the pleco is on his last good nerve, in a good-natured way. He was reluctantly sharing his zucchini with 2 babies this afternoon, alternately flexing his sailfin and shaking his tail- to no avail. They ain't skeered, so he's got to get used to it!
Sorry this is so long- in closing, I'll just state that the general feeling of well-being I get from the clowns since their little pack increased, has gained about 1,000 smileys!

Kate