Mind you, I am not saying there is an existential possibility of a better policy, but the calculus would be nowhere as trivial as this.

I mean, certainly, but it's like having a club on your car's steering wheel: it's not about creating perfect protection, it's about ensuring your car isn't the softest target for theft in the parking lot.

If Cuba had fewer reasons to talk to Russia and China, then Russia and China would have fewer reasons to talk to Cuba in particular, vs. other Caribbean and Central American nations. Which would, potentially, spread their resources thinner and decrease covert-ops ROI, as they'd be having to engage with several nations who only weakly want them there, instead of one nation that desperately wants them there.

(And yes, I do realize that these powers do already engage with other nations in the area, e.g. Nicaragua. But not in the same way / not for the same reasons.)

Also, if you want to talk about countries that the US actually gives "special attention" to, I'd more compare/contrast to the relationship between the US and Panama.

Cuba would have do what those other ex-USSR satellites did and discard communism and authoritarianism in favor of democracy. Then, yes, seeing themselves as a sovereign state would be a good thing.

But I'm not sure if such an alignment could be created between the US and Cuba while Cuba remains a communist authoritarian hereditary dictatorship, since there's no shared enemy nearby and no strong shared economic incentive. Seems like the only real alignment would be Cuba becoming a democracy.