Glad to hear the pup is feeling better. I have no experience with the foods but just looking at the ingredient labels, the formula for "Regal Puppy Bites" is comparable to the "Fromm Puppy Gold"
From a pure ingredients point of view, I'm inclined to say the Fromm is slightly better since there is "grain sorghum" in the Regal which is a low quality grain used primarily as livestock feed. Also Regal uses dried beet pulp whereas Fromm uses tomato pomace, both are fillers that are pretty much unavoidable in kibble but tomato pomace is slightly better.
But the important thing is the pup is doing well on it. You may want to eventually look into "grain free" kibble further down the line since dogs aren't meant to process grains. Or look into something more healthy like a raw diet.