OP, I think you have to realize that this isn't a race. The goal isn't for you to be a doctor the quickest, nor is the Adcoms goal either. They want to see what they need to to assess your likelihood to be successful on this path. Some people have accomplished so much in college it's pretty clear. Others take a year or two longer to prove themselves, but it's the proof, not the timing, that Adcoms want to see.
In some of my older posts, I suggested that in retrospect a lot of premeds would be better off for admissions purposes taking none of the prereq courses in college, get a high GPA in some other area of interest while doing some fun ECs, and then do the prereqs in a postbac, without as many distractions or other course load hurdles, so they could really focus. Med schools aren't about getting this done fast. They would rather you took these things later for an A than rushed earlier for a B. Same thing with ECs -- if it takes you longer to have a better resume for med school, then maybe you spend the time.
There is no prize for finishing your prereqs and ECs first -- the only rewards go to people who get all their ducks in a row and submit a really strong med school application. If you think a med school is going to say -- this persons application is pretty sparse, but let's give him some slack, he's only a junior, it won't happen.