I'm more interested in measuring the obviousness of "think tanks are just partisan rationalizers." I've been disappointed in a few since 2015 thinking, "they'll stand up to this!" then watching the flaccid response. But why would they -- they're donors love it.
That's almost exactly what I think they are: computers for finding simultaneous solutions to both concerns. If you took out the group interests, they would allocate attention *very* differently. And given group sorting into parties, partisanship is extremely predictive.