I realize it’s unorthodox, and to be fair it was only a brief consideration after having watched SAC.

I honestly think the supporting characters are a bit flat in the movie. It adds some depth and personality to some of the scenes as well as explains the social political environment a bit better.

Neither are canon to each other, nor the manga (which I am about to investigate to confirm), but the manga was quite popular so fans already had an understanding of so much when they watched the movie.

Now, outside of the fact that the new anime appears to be continuing with the Tachikomas of Stand Alone Complex, the rest of the franchise appears to be watchable in about any order.