Going to add a little Widewingesque commentary to emphasize my point.
I've been flying the 190a5 a lot this tour. I'm 98-11 in it. Thats a pretty decent record for me. I'd say my average kill tally per sortie is probably around 3, maybe 3.5.
I spent the day flying the N1K2. I look at the Niki as a super 190a5. It is about the same speed, but it does everything else better. I flew 6 or 7 sorties (don't remember exactly, but I know I landed 2, died 3, and ditched once.. so I'm thinking 6). My record for the N1K2 for the day was 63-3. Once was a cherry-pick, two were spits that blew the tail off with a snapshot. One of the sorties was a pretty decent vulchfest, I think I ended up with 18 or 19 kills that sortie (about half of em were vulches). One of em was a really outstanding A2A sortie with 17 or 18 kills. The rest of em were the "average" 5-7 (which is still about twice as good as my 'average' 190a5) kill variety, with the exception of the cherrypick sortie.. I only got 5 that time.
Anyway, the Niki is just about the same plane as a 190a5.. you can fly them the exact same way. Only difference is the Niki has about twice the firepower, and it turns really well (and it is great low speed handling). So if you happen to get bounced by a high Spit while you are in a Niki... you've got a MUCH better shot at surviving. If you happen to get ganged by 2 or 3 guys... you have a MUCH better chance of surviving. You aint gonna run away from much in a 190a5 (not in the MA anyway.. in a 1v1 you could get away from the slower planes), nor in the Niki... but you have a helluva lot more chances to kill the people fighting you if you are in a niki (or a spit) than if you were in a 190.
You might think the plane isnt the most important variable... I'll have to respectfully disagree. After all... why did you chose the Spit 5? Why not the 109f4 (or 109e4 if you really want to be a masochist)... or the 202, or the P40, or any of the other slow "early war" planes. I can make a guess, no idea if it will be right or not though. You picked the Spit 5 because it has enough firepower to kill reliably with the most fleeting of snapshots, it accelerates well enough to keep up with the "late war" planes in a dive, and it has the most outstanding handling of that "class" of planes. I realize you may not care that much, but you could prove me right just by flying the 109F4 for a day. Fly it the same way you'd fly your Spit 5, and you wouldnt have anywhere near the same amount of success you have in the Spit. Hell, you could even fly it the way it was "meant" to be flown, and you wouldnt have much success in it- because the N1K2 and Spit 9 utterly dominate the 109F4, and make it pretty much useless. The spit 5 can at least out-turn the niki and spit 9, unless there is a horrible pilot in the spit 5.
Actually, maybe thats why we disagree. You fly a plane that is considered "inferior" to the "top of the line" planes.. but your plane still has one advantage that a "good" pilot can take advantage of (at least against a "bad" pilot)... I fly a plane that is completely inferior in every way to 3 of the "big 4". Something to think about anyway.