Here's my experience so far:
Glosso is pretty even as a carpet, will definitely grow over itself but won't end up uprooting itself. Very fast
Marsilea Minuta is a slow grower, but stays pretty even and low with high light.
Hydrocotyle can be clean and even, but requires a ton of trimming to be trained to stay that way.
I have belem, HC and UG growing emersed, so I'm still trying those out.
Glosso is pretty even as a carpet, will definitely grow over itself but won't end up uprooting itself. Very fast
Marsilea Minuta is a slow grower, but stays pretty even and low with high light.
Hydrocotyle can be clean and even, but requires a ton of trimming to be trained to stay that way.
I have belem, HC and UG growing emersed, so I'm still trying those out.