That's a tricky one. The first thing I look at is to try and figure out what they mean by "crude protein". There was a time when melamine was added to pet foods to increase the crude protein. Melamine is used to make plastic type stuff, it sure isn't a food. But the way the crude protein is determined means non-food or poor food items can be added to let's say fool people.
So when comparing if fish meal or fish type stuff is the first ingredient I expect to pay more than if grains and animal proteins are list first.
Then there a game they play, like Keytee does. Here's the start of their ingredient list.
Fish Meal, Ground Corn, Dehulled Soybean Meal, Wheat Flour, Corn Gluten Meal, Fish Oil, Wheat Germ Meal,...
Isn't ground corn and corn gluten meal basically the same thing? Yep. But together it probably means there's more corn than fish meal. They do the same for wheat. So my guess is listing fish meal first isn't actually true by what I care about. But fish meal is in the running, so not exactly "bad" either..
But that's just me not wanting to pay more than it's worth. I don't have a problem with using less expensive food.
I've fed trout chow/catfish chow before, not great food, high fat, but it's cheap. Guess who else eats a high fat diet? Me. But I've never been a heavy feeder or fish, 3-4 times a week. If I was feeding several times a day, or had an auto feeder, or wanted show fish, then a high fat food would be a bigger issue.