I think a handshake deal with Schwartz is pretty wishful thinking. For starters, I'm not sure what incentive Schwartz has to do that. Every player is one bad hit away from their career being permanently damaged. Let's say that there is a handshake deal for a contract worth $35M. Schwartz goes into the boards terribly and breaks his femur a week later. How confident are you that the Blues honor that deal? Are you willing to bet $20M or so that Army will honor that handshake deal?
Let's say you do value Army's word at around $20M and are willing to make that bet. What is the incentive to lock yourself into that contract? If you get exposed in the expansion draft, Seattle has a week to negotiate a contract with you before the expansion draft. What if they call your agent and offer you $45M? Do you honor your own word at the expense of $10M? Bear in mind, you can't tell them that you have a deal with the Blues as doing so would create a pretty open and shut case of cap circumvention.
There is absolutely an avenue where you expose Schwartz and both sides keep the possibility of an extension open if he doesn't find a better offer on the open market (and "better" includes whatever value staying in St. Louis has to Schwartz). But there is zero incentive for Schwartz to promise not to explore the market while continuing to risk an injury that causes that promised-extension to evaporate. He and his agent would have zero legal recourse if the Blues declined to honor a handshake deal, so that risk is completely tangible.
If I were Schwartz, I would laugh in Army's face if he suggested that I risk tens of millions of dollars so that the team can protect one extra depth forward. If I was willing to negotiate after that, my starting point would be a full NMC for the duration of the contract. After all, if I'm taking on this risk for the team, then I need some assurance that I'm on this team for the duration of the contract. That is a defined non-starter for Army, so that would pretty much end negotiations about a handshake deal.
