I think using the CHE is fine, as long as there is plenty of light in the enclosure. Bearded dragons really thrive on light, and many believe the brighter it is, the better off they are. That is mainly why most choose to use heat lamps, because they provide heat and light.
I don't have any experience with the UVB light you have, I use the reptisun. Hopefully someone else can help w/ that.
I must say though, since you mentioned having three, unless your are 100% positive they are all females, you will most likely have to seperate them eventually. Especially if they are siblings. A male and female sibling will breed, and inbreeding is a terrible thing that shouldn't be allowed. If they aren't siblings, the males and females should still be seperated until the female is old enough to breed (1.5 years) because allowing them to breed too young can lead to health problems. And finally, having any more than one male to an enclosure will most certainly lead to fighting, injury, and possibly death.
That said, if they are all female, you may be able to let them stay together, but there still may be fighting and dominance issues, so watch out for that. If it happens they'll need to seperate too. Beardies are territorial and will not think twice about nipping off another's tail or toe if they feel like they need to show who's boss.
So be sure of the sexes, provide plenty of space, and plenty of food so they don't feel over crowded or in competition with each other. Housing multiple beardies together can and has been done, but it requires a delicate balance of all those things, and proper caution.
Good luck!
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Amanda
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2.0 bearded dragons (Ocho / Domo-kun)
0.1 kingsnake (Rio)
1.0 ferret (Playstation)
1.0 cat (Wally)
0.1 dog (Tima)