I don’t agree that one generally wants maximum optionality. Too much optionality for first strikes makes you a bigger threat, which may worry others to the extent that they first-strike you. If, say, the Jamaican government woke up tomorrow to find itself in posession of nukes and launchers for them, it would be a headache for them, they’d probably wish it never happened, and try to conspicuously give up the weapons, so that other nations didn’t view them as a nuclear threat. Giving up first-strike options can often make you safer, which I don’t think is true for second-strike options.
I don’t agree that one generally wants maximum optionality. Too much optionality for first strikes makes you a bigger threat, which may worry others to the extent that they first-strike you. If, say, the Jamaican government woke up tomorrow to find itself in posession of nukes and launchers for them, it would be a headache for them, they’d probably wish it never happened, and try to conspicuously give up the weapons, so that other nations didn’t view them as a nuclear threat. Giving up first-strike options can often make you safer, which I don’t think is true for second-strike options.