This site suggests Poseidon accuracy could have been far better, how true is the suggestion?
http://www.designation-systems.net/dusrm/m-73.html
The low-yield warheads were deliberately chosen so that Poseidon was not suitable as a first-strike weapon against Soviet hardened strategic targets, but very effective as a retaliation weapon against "soft" targets (like cities). Because it was feared at the time, that an effectively invulnerable high-precision high-power SLBM would destablize the nuclear balance of deterrance, the development of a new stellar-inertial guidance system and high-yield warhead was not approved by the Department of Defense.
http://www.designation-systems.net/dusrm/m-73.html
The low-yield warheads were deliberately chosen so that Poseidon was not suitable as a first-strike weapon against Soviet hardened strategic targets, but very effective as a retaliation weapon against "soft" targets (like cities). Because it was feared at the time, that an effectively invulnerable high-precision high-power SLBM would destablize the nuclear balance of deterrance, the development of a new stellar-inertial guidance system and high-yield warhead was not approved by the Department of Defense.