I don't know... what does Cadillac tell all the professional athletes, rappers, movie stars, etc., that have grown accustomed to the Escalade? The aren't going to buy used ones, they'll migrate elsewhere if they have to. It seems every luxury maker besides Acura and BMW have a small ute (BRX), midsize (SRX), and large (Escalade). We'll have to agree to disagree, I guess.
Perhaps Pontiac does need the ST, and since it's probably easier to do it as a Pontiac than a Chevy, it is fine to do it that way right now, but in the long run Chevy offers more market coverage, I think (with sport, utilitarian, and basic models). I think Impala and G8 can be well differentiated. Right now, the G8 is too big, IMO. It should be 5er sized, not 7er sized. Alpha = 3er, G8 = 5er, Impala = 7er (or perhaps bigger) in terms of size.
By Lucerne/Park Ave I meant one or the other (basically just a name), not both. What do you feel is wrong with the Enclave on Zeta? It seems it could make it more premium than its platform mates, which it should be.
I don't know, I think Lambda is more truck-like than Zeta, but we don't know exactly how versatile either platform is. The Ridgeline is fine for running to home depot, and I don't think a Zeta truck is going to be any more capable towing and hauling than a Lambda truck. Lambda is also a bigger footprint to start with.