Limania highlighted the problem we have, not sure about others but mine get communal watering from a hose in summer, and watering can at other times of year based on need rather than species. I saw someone on facebook advocating watering sensitive species with a pipette the other day, which did make me laugh. The thought of going around 1000 seedling putting a couple of drops of water to each seedling..
I can just see that happening in my greenhouse.
The only species that gets more water than the others is Lithops optica rubra which is still being watered by watering can now. And it still hasn't finished flowering.. It also tends to lose its leaves later during the summer so possibly I try to avoid water for them too early in the season. I say possibly because that is perfection, it is quite likely they will get splashed by my enthusiastic hosing..