lvl 3 beetles are like having 5 perm, no food free ghouls. beetles are no gold, ghouls. in mirror matches the differnece is decided by the fact u have 5 extra soldiers.
CL beetles actualy provide the required meat to get fiends in ud mirrors, but it usualy requries you to get otehr units cause fiends suck hard.
Late game, beetles become useless. eventualy they become dispeled fast. what is great about beetles, is u can put a second skill point in it, and u get an invaluable scout. starting with beetles, going to lvl 2 with them, then switching over to foucs on impale is very good. basicly, beetles lvl2 get burrow. as they have no food cost, and have no expire timer u can keep them around to scout the map for the entire game. they beat out wards(to bad they cant detect invisible like wards however.)
Problem I have with CL, Is I find I really need to get DK second, cuase CL is incredibly slow, and he is usualy taking alot of hits, so coild is essential