hi kbfchicago - I'm jmalter, not jmiller. But no worries, mate - twice at least in the past months I've referenced Albert as Alfred!
I've no opinion on the 'include 1 experienced pilot' issue, but I'll give it a try in my next game.
I really am convinced on keeping an airgroup's pilots Exp levels as close as possible - less than 5% differential, except for the command pilot, his Ldr/Insp skill is more important. If I've got a decent commander, I'll keep him - let's say I've trained up a medium bomber group to 70 ASW, but the commander's ASW is <20. When this group goes operational, I'll put the commander on group reserve - he won't fly missions, but his Ldr/Insp stats remain in effect.
For training groups, if Exp levels are v. similar, the pilots train the selected skill more uniformly - lesser-skilled pilots get more attention than higher-skilled pilots. If their Exp level difference is too great, the higher-Exp pilots get less training improvement.
For operational groups, the higher-Exp pilots fly missions more often than the lower-Exp pilots, even if the lower-Exp pilots have = or > mission skill. This can lead to a higher accrual of group fatigue & morale loss.
Another of my personal rules - I always keep my groups at 133% pilot strength, even if I must add lower-Exp pilots to an operational group.
While I try to optimize pilots on a semi-regular basis, sometimes I have to do a yoogly click-fest, involving dozens of airgroups & 1 or 2 thousand pilots. If I don't make interim saves during this procedure, I often get a game-crash when I run the next game-turn. Take note! All your non-saved changes are lost, & you'll have to do the pilot-transfers all over again.