The biggest problem signing Matthews was luxury tax hit this year. Next year we are shedding 18 mil of AK salary and get some relief. We don't need to sign a replacement SF, because we just drafted a SF with top 10 pick, who will be under contract. Take a look at the numbers: https://hoopshype.com/salaries/utah.htm
And for this year, Wes counts 5.7 mil against the CAP. Raja counts 3. So, we are not talking about crazy difference this year here. Perhaps if we kept Wes, we wouldn't sign Raja and Elson. Would you rather have a young player like Wes over 2 guys near end of their careers, like Elson and Raja. The difference in salary is only 1.1 mil. Raja is struggling to produce now what Wes did last year in his rookie season. And Raja will only get worse. For the difference in salary, isn't it apparent now that we should have kept a 24 year old guy, who in second year, when starting, is producing nearly 20 ppg on good shooting and playing good defense? Jazz made a huge blunder here, and I am not sure why there is even a debate on this given today's performance of the players in question and their upside (or lack thereof in case of Raja).
Dont forget there was also a very large signing bonus and when you consider luxury tax it is really double the difference.