Luka Dealt to Lakers: Nico Harrison is a Basketball Terrorist

[Dahlsim]

Ok let's assume he was right and we weren't competitive against Boston ... So the choice is to further lose competitiveness, set the window to 2/3 years, leave the Mavs without future picks and also lose a lot of money from marketing/TV/sponsors/tickets/etc etc

I'm sorry, i can't believe that someone is so stupid.
That's a collusion.

No doubt Nico colluded with his Laker buddy.  Still could be that his intention for Dallas was do what he thought could give the Mavericks a chance to win a chip in the short term.  

set the window to 2/3 years, l

When Nico was asked about longer windows like 5 to 10 years I thought he answered pretty honestly when he essentially said he doesn't think of the franchise future that far out.  He said something like who knows if i'm alive or where I'll be that far out.  Not to say it's a great answer if you want your GM to plan for the long term future franchise but in his mind he had Dallas has win-now mode. 

In that respect he may well have thought AD + Max with Kyrie was better in the short term window of 2/3 years just as you said.