Marines are the face of the world government, akainu is literally the one opposite of luffy freedom, and unless hes defeated he's going to keep spreading to marines his justice.
Akainu killed ace, gave luffy his scar, broke his will.
Sabo vs akainu is almost as bad as shiryu vs mihawk.
I normally agree with your points but this one I disagree with.
Sabo has aces will as he stated.
Has to make up for not being their
Has to show fire becoming more powerful than akainus magma as revenge.
Has to get revenge on behalf of his brother.
Also has to partake in his brotherly duty protecting his little brother.
It also build akainu being the major face of the marines while sabo is currently the face of the revos
Dragon and luffy vs imu makes a ton of sense.
Dragon for obvious reasons and luffy since it would be the first time him meeting and working with his dad. Also makes sense with the while Nika situation. Akainu is also a lapdog to the world government and in extension imus bitch. Luffy defeating akainu changes nothing since they will find another him to take his place .