The bolded is mere speculation on your part. Collison signed here because we offered more money than anyone else, including the Clippers who had other plans with their money. In fact, Collison himself considered returning to the Clippers had the money been there. Unless you can show that there was some kind of promise that Collison would be the starter, without which Collison would have signed elsewhere, it remains a twisted interpretation of the progress of events.
Here are some facts that question your interpretation of the situation:
1) The Kings signed Darren Collison before Isaiah got his deal with the Suns.
2) After signing with the Suns, the Kings had the option to match and declined.
3) Isaiah is currently coming off the bench for the Suns.
4) Last season he was coming off the bench behind the utterly useless Vasquez
Isaiah wants to start and will compete for the starting job. But so far he's done nothing but played excellently off the bench. So if you wanted to start Collison, you could have started Collison and kept IT.
And even if you wanted to eventually let IT go, PDA could have kept him as a trade asset for later use. He didn't. He chose the trade exception. Thats not a "straw man". That is reality.