Why try to functionalize Aikido instead of do a more "practical" martial art (the most common suggestion being BJJ and/or kumite point fighting)? Because your alternative you have suggested isn't going to get the Aikidoka what they are striving for. There are two issues here: first is technique, and second is ideology.
There are three ranges of Aikido technique.
- First there is stand-up grappling, what they would call "clinch" in MMA or Muay Thai. In the case of Aikido it is paramount that they stay on their feet, because it is a self defense oriented system (rather than a pit fighting system) so that they must take the possibility of multiple attackers - who may not yet even be identified - seriously. The only traditional unarmed Budo with this exact objective is Sumo, and Sumo influence on Aikido is no coincidence. This type of grappling is common in other internal martial arts in the form of Push Hands and San Shou.
- Second there is knife-range techniques. These include both disarm techniques AND attacking techniques. On one hand being attacked with a knife is one of the most important self defense scenarios to train for, while on the other hand pulling a knife is one of the most practical ways to fight off multiple attackers.
- Third there is a walking stick self defense system deeply encoded into Aikido, for the obvious reason that a walking stick is one of the most practical non-lethal ways to defend yourself known to humanity.