Signing Thome was basically a new stadium marketing ploy, and they traded Lee rather than pay him.
There is a different approach with Middleton, it's good when your GM says "don't throw money away, we have better ways to spend your money."
And they have traded for allocations, so they're quite aware of what it takes, and they're willing to move marginal prospects for allocations.
For all we know, they had a list of Brave prospects, contacted their agents, and found out they had committed elsewhere so they couldn't spend the money if they wanted to.
They spent $60M last year on short-term deals for FA, so Klentak is not adverse to spending.
And of course, things may change rapidly, often deals are underground until their announced, good GMs aren't desperate to advertise that they're doing something, they often play things close to their chest until the deal is done.