Can I convince my partner to do triple P?

Hey beautiful ladies!
I am struggling with my partner at the moment- some background info is that I have an 8yo son who is autistic and we share a nearly 2yo daughter.
My partner and I separated for about the last six months of last year. We reconciled and overall I think we are happy. However, I am really struggling with his parenting style. He is very disciplinarian and authoritative especially towards my son. We have spoken about it on numerous occasions and can't see eye to eye. He thinks I'm too soft and I think he is too strict. We both want the same level and type of behaviour but can't seem to agree on how to achieve this. I really believe he would benefit from completing a program like the triple p positive parenting to learn new strategies. Especially for my boy (I really should say our he does adore my son and my son adores him). I think he just can't understand why 8yo struggled so much with quite repetitive things like it's always the same issues and he can come across quite argumentative and defiant but I honestly believe a lot of it is the inherent characteristics of his autism. Has anyone had success convincing their partner this sort of thing would be beneficial for all involved?
I have considered just leaving because I have quite high expectations for how my children should be treated but we have separated and reconciled- there is a lot of love between all of us. My son voluntarily calls him Dad and they mainly play and have fun it's just when there is a need for discipline I find myself disappointed.
Thanks for listening ladies.
I will add some improvements were made when my partner started coming to specialist appointments and could see that there was someone else saying what I say. That's why I think a program would be good for all of us.