Pilots: US>KM=MN=RM>SN>UK=IJN
FP planes:
US best overall.
UK bad overall.
IJN good for killing T5 scouts, bad at scouting due to -1 sightrange and overall bad at dogfighting.
KM good for dogfighting and scouting due to high firepower, bad at hunting T5 scouts.
MN average values in all of the stats of the 4 nations mentioned above.
SN bad at hunting T5 scouts, average at dogfighting, bad at everything else.
RM From average to above average stats, so pretty decent FP's.
Conclusion: US has the best FP's followed by RM.
KM and MN are OK.
SN is just below average and IJN & UK are the worst kind. These 3 also happen to have the best DB's or TB's.