I think you need to be really clear, in your own mind firstly, what it is that you are fighting for. We all have that instinct that our child needs stability and the best. For as many children who are excited about the new chapter in their lives, there will be children who are anxious, scared, or down right terrified.
From a panel's point of view, look at your arguments objectively.
~Your DS doesn't like change: Ok, but change is coming, wherever he goes.
~Your DS wants to be with friends: OK, but he'll move to a school with, say, 1300 children, which is 300 to a year group. 10 classes, so 10% chance of being in the same form class as his friends and even then, about 8% chance of being in the same teaching classes. That's using the example of DD2's school, where the year group is split in half for timetabling, then split in 6 within that for their main lessons. Then they're set for maths, science and PE.
So putting friendships aside, because honestly that's a really common argument and also a really weak one, what is it about your preferred school that your DS needs? Go from there. Don't just say 'SEN provision', especially if he hasn't got established SEN. Be really specific. Talk to the SEN departments of all 3 schools and find out what they would do for your DS.