Small BG will likely take CC feed if it is small enough for them to handle. A 4" BG may have trouble with pellets 1/4" diameter or larger; some CC feed use bigger pellets than this.
CC feed is often lower in protein than that intended for BG; protein % in the 28-32 range should be suitable for "supplemental" BG feed. Find out what % protein the CC feed is and the fish nutrition experts can give better advice.
LMB hardly ever take pelleted feed unless trained to do so. They do learn to love hanging around with the BG at feeding time where they pick up pelleted feed second hand.
CW that I agree with:
Feed no more than what your fish will consume in 10 minutes, as wasted feed hurts your water quality as well as your wallet. BG and CC will usually eat more than once a day (if you can feed them that often) in the warmer months. Don't exceed a total of 10 pounds of feed per acre per day.