Thing is, it's possible to classify, for example, chemistry as being a branch of physics ("It's basically all about the interaction of electron shells"), but that classification isn't very useful - chances are that faced with a pretty average chemist and a really good physicist, you'd ask the chemist every time if you wanted to know about chemistry at any level from the most basic upwards.
It may be useful, for example, to count digital electronics, analog electronics, power systems, etc as part of electrical engineering, but despite the clear historical link, it may be less useful to think of computer programming as a branch of electrical engineering (and that's even acknowledging that many elec. eng students may do a fair amount of programming alongside their other studies.
Effectively, the disciplines have evolved to the point where the practices and concepts are different, even if someone may well use both disciplines when actually working.
Reading Popper (or, for most of us, reading some brief summary of his ideas), may help codify once implicit/subconscious concepts so that they may be more clearly talked about for intellectual entertainment, but does pondering on the philosophy of science actually have much effect on science itself?
It could be useful in the sense of giving the ability to more formally explain why some nonscience isn't science, but people were still pretty much as able to make that distinction pre-Popper, even if they possibly had a less formalised means of explaining it.
A philosopher isn't really needed to understand that theories are only provisional truths, since a quick look at the history of overthrown or modified old theories can illustrate that fairly adequately.