I also don't encourage critters to be introduced as a problem solver (algae eaters for algae, loaches for snails, etc) but I have 1 exception to the rule...
I purposefully introduce MTS to all my tanks for their benefits- eating algae, aerating the gravel, etc. and sometimes ramshorns for algae cleanup. (Not to get rid of an infestation, but perhaps to clean up once the problem is resolved)
The only reason you would want to add another bulb, is because with higher light, CO2, and ferts, the plants grow faster. Faster growth does mean less stable in most cases... (plants grow fast, and outcompete the bacteria, which isn't really a problem... until you trim the leaves, and trigger a cycle because the plants can't use all the ammonia anymore)
If you added another bulb, you would probably have to consider CO2 supplementation (along with constant ph and nutrient monitoring to know when to dose. High-tech can 'crash', with disasterous consequences for plants and fish.)
I'm plan on setting up a "middle-tech" tank soon, but it's strictly for selling plants. I want to see if it's profitable, even though it probably won't be. (I have 2 unused 10 gallons right now, so meh.)