The main executable file, `Sourcetree`, is universal (x86_64 and arm64), but the git binary utilities are not.

$ file Sourcetree
Sourcetree: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64Mach-O 64-bit executable x86_64] [arm64]
Sourcetree (for architecture x86_64): Mach-O 64-bit executable x86_64
Sourcetree (for architecture arm64): Mach-O 64-bit executable arm64
$ file ../Resources/git_local/bin/git
../Resources/git_local/bin/git: Mach-O 64-bit executable x86_64

git runs translated by Rosetta 2. It works but with suboptimal performance.