I think you've misinterpreted. I believe he gave Stek a 2-year deal in 2018 because he wanted him as his back-up, which is fair, he was 35 at the time which isn't exactly past it for a keeper and wasn't a liability when called upon. Then in 2019 - as you said yourself - "bringing in international keeper who's been a number 1 keeper pretty much all his career (and all at the top level)" when he was available on a free was a smart move and one he thought wasn't worth missing out on. Brands was then left with Stek with one-year left who he could try sell but in the end he couldn't and he'll just leave this year.
When Joao Virginia was coming back in my eyes he thought "right, 4 keepers. First choice, one we can't sell, a young lad who needs his confidence rebuilding and a back-up on £38k per week" so that's why Lossl went off out on loan to shave money off the wage bill.
Maybe I'm looking too deeply into it but in my eyes it's all very straightforward and calculated.
I think we wanted 3 keepers. Last year Virginia was 3rd choice, this year they wanted to loan him out for experience and so they needed another keeper. I don't think selling Stek was ever considered for that reason. Signing Lossl seemed, at the time, to be a reasonable decision. Free transfer, experienced, used to being number 1, could theoretically challenge Pickford and lead to improvement. Stek is then your 3rd choice, unlikely to be ever used but competent in a disaster. In theory that's all fine.
In practice, Lossl turned out not to be a challenge to Pickford, and in fact didn't even establish himself as second choice. That's why I think it's fair to include him in criticism of the summer business, because I don't think he did what he was bought to do, and because of that he became a totally unnecessary signing. If Stek was going to be on the bench half the time anyway then we could have just brought in a nobody to be third choice, on much lower wages/signing on fee. As I said, Lossl is a long way from being a massive problem, and if the rest of the business had been good it wouldn't even warrant a mention. When talking about the business not being good though, I think it's more than fair to include him.