Not to disappoint you but HC does best to carpet with the dry start method. The plants can easily root in a dry start condition than fully submersed. Glosso would just need medium to high light with A LOT OF CO2. If any of these plants were originally grown emersed, it would take time, few weeks, to transition to the submersed form. Assuming the plants didn't die within the transition period.
You may want to do a search on how to carpet with either Glosso or Baby Tears. You will be shocked in how much you don't know. How much you aren't really prepared to grow them.
To be quite blunt, the carpeting of HC is pretty easy to do in a submersed form provided that you have the necessary setup. One can do a dry start if they would like, but I have had equal success with both methods.
They key to growing submersed is to keep an eye on the HC, and adjust ferts and CO2 accordingly based on how you are seeing growth. In my experience HC is not a high light demanding plant; it is a high CO2 demanding plant. Getting this plant to carpet is more of a battle in fert adjustment and dialing in CO2 rather than blasting with light.
That said, one can run into significant problems with dry starting HC, including mold, extreme die off once submersed, plants uprooting if not properly given time to grow in dry start state, etc. etc.
Glosso cannot be transitioned well to submersed from. Almost everytime I have tried the dry start to submerse form I lose at least 90% of growth and have extreme rot no matter how much or little CO2/light/ferts are given.
HC carpets also do best with fine grain substrate; I have most success with ADA powder; the larger stuff tends to inhibit lush carpet growth for me.