He's an upgrade over Diggs for sure, but he has a lot of the same downsides as Diggs. He's also progressively gotten worse over the years. He really struggled in run defense, lots of Packer fans are just meh about the guy.
Regardless, safeties play a huge role in MacDonald's defensive scheme and our guys have been liabilities lately. In MM's defense, safeties have to be able to do a little bit of everything. The traditional duties and designation of FS and SS need not apply here. His safeties do everything from function as an extra linebacker, to being kicked out to the nickel position. I don't think Savage fits that ethos.
I have a sneaking suspicion that MM is going to kick Witherspoon to the Hamilton role, as Witherspoon was already doing something similar here. In fact I'm almost sure Witherspoon is going to be a safety come September.