I might suggest breaking down fights into two other categories and see if Aikido makes sense:
1. fights where a solid strike connects; and
I used to know a former military police officer stationed overseas and he used to get in a lot of scrapes even when he was off duty
and he told me that most fights end when the first solid strike is taken. I think Aikido makes sense in this scenario - the atemi implied in all Aikido techniques - however expressed - ends the fight if fully realized. In an Aikido setting, uke reacts to nage, nage takes balance and pins.
In "real life" setting, nage puts hand in uke's face, uke doesn't react or block or evade, nage puts hand through uke's face, fight over. Or, uke blocks, evades, counters, nage, continually moving, puts hand in uke's face, etc.
Okay, it's very simplistic, but...
Oh, and scenario two? grab a pen, keys, stick and start poking and biting and chewing.