>>14134215You can see the engines here are off axis.
With Starship, the only reason to go for a 'stage and a half' design would be to cut dry mass, in the form of engines (+ likely some thrust structure and vertical load strengthening), off the first stage by gaining the extra engines from the second, however if you get major cosine losses from a shifting center of gravity or you have to considerably throttle, then you lose that thrust anyway.
I personally think the reason why dolphin sex 'might' work where starship doesn't, is because it's harder to stack planes on top of each other, so it becomes beneficial to stack them side by side.
I think that might actually be a bigger consideration than a potential marginal performance increase.
Likewise you also have to consider the efficiency of your second stage as well; if it now has to fire at sea level you are going to be losing vacuum ISP.
Take starship; you would only be getting 3 extra raptors to lift you off the pad in a side by side configuration, the vac-raps are still going to be dead weight until you have burnt off a lot of fuel anyway.
