Hang on, so at the moment, you get the schooldays - so you don't actually get to spend daytime hours with them, and when they're home, you get the homework/sorting out uniforms/early bed etc. to organise? And he gets to take responsibility for none of that, and instead has two days of fun and games?
Right!
I completely agree that for dear Dad to have two days a week only is grossly unfair. 
I would suggest, firstly, that weekends are split equally. You both need equal weekend time, equal downtime with the children. So, every other weekend, he has them from Friday evening to Monday morning, and takes them to school that am. Over the weekend, he naturally washes and irons the uniform they came home in, and they go in in that uniform on the Monday. So there is no need for uniforms in bags etc. He sorts sandwiches/lunch money, games kit, homework, EVERYTHING.
The other weekend is completely yours.
Then - the weekdays. I would suggest that the weeks he has them on the weekend (now three nights) the rest of the week they are home with you. The weeks he doesn't have them on the weekend, he picks them up on Monday, and they go back to his for either two or three of the school nights. Homework, uniform washing and ironing, packed lunches, games kit etc. etc. - all of this to be split in the way which makes it easiest to work for BOTH of you.
So. He gets three nights a week. But he ets three FAIR AND REPRESENTATIVE nights a week. He does some of the shitwork, as well as enjoy the fun and games.
Now, I have a feeling Mr. Superdad isn't going to go for that, but I may be totally wrong and he is itching to spend some evenings a week ironing school uniforms. Do report back!!