Use a spray bottle to help water close to rosette and definitely need to monitor amount of water if there's no drainage.
Not sure if those semps are small because they are babies of larger type semps or if they are already at adult size, but if they grow too much bigger the scale of plant to garden may be off. I guess you'll see as time goes by and when they get too big you may want to trade them for ones that do indeed stay small because of their cultivar background.
