Supposedly wing configuration makes a substantial difference in drag. Long story short, mid-wing aircraft were regarded as having lower interference drag given certain angles of attack. But the reason is more complex than I remember.
I wouldn't normally link to Quora for a WW2 discussion, but the summary in
this post is so good I can't help myself.
Low-wing and high-wing had the highest amounts of interference drag because the interaction between the fuselage and the wing position exerts extra drag on the fuselag in high and low-wing configurations. The mid-wing position has the lowest amount of induced drag.
According to
this Stackexchange post, there are a lot of other reasons for why a midwing configuration is used on fighter aircraft. The differences relate to production, performance, and structural integrity. Some of the most salient differences include:
- Lighter weight of the bulkheads that attach to the wing spar.
- Heavier weight on the carry-through spar in the fuselage
- Weaker ground effect (negated on a carrier aircraft)
- Better performance in a roll
- Poorer visibility while maneuvering
- Heavier landing gear (unless an inverted gull wing is used)
I always assumed that Grumman used a midwing (or somewhat midwing) configuration on their aircraft for this reason. Although considering that the Hellcat was the slowest Allied fighter of its generation, a midwing configuration couldn't have contributed much in terms of total speed. Although the Hellcat also had a big wing, large profile, and used a non-"laminar" airfoil, so that's probably a big reason why the dash five probably only barely made 400 MPH even with insanely good fuel and a powerful engine.
A high-wing aircraft, on the other hand, is probably more suited for lightweight recon aircraft. The high-wing makes for great downward visibility. But its landing characteristics and interference drag make it a worse candidate for a high performance fighter aircraft.