I feel kind of foolish saying this, but if you are trying to compare
any single concentrate to a vendor's pre-mix, I hope you are factoring in the likelihood of the vendor using multiple ingredients. I imagine that there are instances of single-flavor premixes on the market but I would
guess they are very much in the minority (no one who is trying to sell a product wants it easily replicated... yeah, yeah, I know, "what about Pet Rocks?"
<
must be a child from the 70's to get reference>).
I have no doubt
which "fish" concentrate they are using is important to replicating it (I know you didn't say that was your goal); but so is whatever else they are putting in it. Are they giving the strawberry a bump? do they add something for extra sweetness or mouthfeel? What about secondary fruit notes? It is possible that they selling a souped-up FW (or ?) fish. I'm sure, as a DIYer, you understand what I am trying to say.