Focus build

Trying to solve my problem of no mid bass in my 07 focus. Not sure whether I should ditch the current speakers, upgrade. Get an amp for the current ones, or both. I have 4 sound ordnance p57’s 2-way speakers from crutchfield, paired with their 10” powered sub, and a boss CarPlay HU. Started out with the speakers and HU, as the factory ones were blown and I wanted the convenience of CarPlay. Recently added a sub to make up for the lackluster bass response.
I’ve found that while the low end has a strong presence now, the mids are arguably worse since there’s decent low end to expose how weak it is. The system in general is fairly cheap, not breaking the bank or winning awards. The speakers are rated up to 40W RMS, they’re ran off the internal HU amp which is “rated” at 20W but with no cert to back it up.
Should I get an amp to power them and try that first, or upgrade and get one?
Also what is the general consensus on adding additional speakers/is it worth the hassle? The car only comes with 4 mounting spots in the door but I know most modern vehicles have more than 4 speakers.
would adding two dedicated mid drivers either additionally or replacing the back two be frowned upon? All externally powered mind you.