It's an immensely capable tool, but it gives no guidance regarding the right way to do things.
There is no right way. Think about styling. Is there a right style? No. It is silly to argue over your code's appearance. HOWEVER! As soon as you start collaborating with people and reviewing code, a uniform style is a very nice thing to have.
Teamwork creates the need for shared conventions. And that's where your ability to convince your team members of the value of some standardizations comes into play.
different projects on my company use different practices...
It sounds like your problem is not Git, but lack of organization. I am not sure a more restrictive scm would fix that. You need to find a good way to use Git, and then sell everyone on the benefits of process uniformity.
If there's no right style, then couldn't the SCM just pick one arbitrarily so I don't have to worry about spending time communicating about something irrelevant to getting the product shipped?
There is no right way. Think about styling. Is there a right style? No. It is silly to argue over your code's appearance. HOWEVER! As soon as you start collaborating with people and reviewing code, a uniform style is a very nice thing to have.
Teamwork creates the need for shared conventions. And that's where your ability to convince your team members of the value of some standardizations comes into play.
different projects on my company use different practices...
It sounds like your problem is not Git, but lack of organization. I am not sure a more restrictive scm would fix that. You need to find a good way to use Git, and then sell everyone on the benefits of process uniformity.