"Don't have stomachs." I don't know whether to laugh, or to facepalm. Who in history came up with that idea? Whoever they were, they didn't take/understand basic fish biology.
Even the living bottomless pits that are goldfish have stomachs. xD And they aren't very big. They just don't have much of a clue when they're full, so their reputation goes.
If it's not broke, don't fix it. If your fish are happy and thriving with your current routine, keep doing what you're doing. If you want to make them happier, though, try more variety, not more frequency. Frozen/live foods are always an option, if you can get them and/or they don't gross you out. Goldies also like plant matter, so there's that option, too.
Also, think of it this way: Higher frequency of feeding means more waste. More waste means more cleaning. That means more work for you in the long run, and the potential of knocking your N-cycle for a loop.