It's worth considering whether firing Montogomery and Whitehead is not for the apparent reasons, performance and/or critical mistakes alone.
Whitehead, for example, is not a guy you'd consider more than adequate and not exactly an answer to a long term question. But he's played better than the other obvious choices for the hybrid ILB role, moving ahead of Jones and Burks playing a full boat of snaps the last 2 weeks until he got ejected.
It's possible over these past 10 months that Gutekunst has achieved full GM status or something close to it, moving past the evident power sharing with McCarthy and Ball where all three were reporting to Murphy. Perhaps, the Montgomery and Whitehead gaffs were opportunities, not reasons. Perhaps Gutekunst wanted McCarthy to run A. Jones more and dumping Monty was a way to make that happen. Same with Burks or J. Jones or even Campbell at hybrid ILB. The fact of the matter is players develop by playing in money games. This is one way to see that they have the opportunity. And if it is the case, that would say Gutekunst is not in entire agreement with McCarthy's personnel usage.
It is worth considering, some food for thought.
As for the guys he's been signing in recent weeks, it looks kinda like 2018 Draft 2.0. These may have been guys Gutekunst scouted and liked at the time. As a general characterization with a few exceptions in the details, they were orginally mid-round picks signed by the Packers to one year (or 1/2 year) deals. They're young players without much of a resume except for Breeland, some with injury histories that derailed their projections. While a mid round pick gets a 4 year deal, there's little dead cap if the guy doesn't work out and gets cut before his rookie opening day. That's these guys too; without doing a full inspection I don't believe there's a dead cap $ among them. It kinda looks like an in-season training camp where the "final cut down" decision is whether they get re-signed for next year.
That's not to say this is just forward looking without consideration of a potential upgrade now. But you could say that about 2018 draft 1.0. You can't retroctively stack good drafts in place of those poor ones, but this kinda looks like an attempt at a cheap, partial substitute. One or more or none of these guys might work out and stick for 2019. But you could say that about the mid-to-low rounders in any draft.