Their workflow was basically "blindly point and click in Visual Studio because I don't understand even the basics of git. I miss the old custom in-house VCS and am very grumpy".
I learnt how to use git years before I learnt to use the git CLI.
The other thing would be to make sure people understand what things like 'squash' and 'rebase' to and how they effect the tree.
Also to explain if you have multiple features, please don't work on it all on the same branch unless you have too. (This is a internal workflow, not really related to git but how we handle merges)...
Yeah, a UI could be just fine for an experienced git user. In my experience though, experienced git users don't use it though, so it's a moot point.
Just a really quick aside...
Do you... say "oooey" instead of "you eye" when reading "UI"?