Cherubs are harem spawners. For the smallest possible harem (3) get two smalls and one larger one. The smalls will stay female (they all start as female) and the large will turn male if he isn't already.
The problem with pairs (which can work if you're lucky, but often doesn't) is that one female has to bare with ALL of the male's harassment. Harems give females some relief by spreading the harassment around. The more females, the easier it is on everyone.
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