"Natural rights" are a joke made up by moralist humans. The ONLY natural right is the right to be stronger and anililate anything and anyone you feel necessary for your own survivial or any other reason. If you are not stronger then tough luck. Nobody owns you anything liberty, life or otherwise.I do not think it is incoherency nor disingenuousness which troubles you. What turns you off is a different core basis for determining government function. One is based upon morality where the defense of embryos enables the state to negate all natural rights of an individual at its discretion. The other is based upon freedom and inalienable natural rights. Neither is right nor wrong on their face but the question remains as to the successful functionality of either approach.
Morality is not a good basis for governance. It is dependent upon a group belief system rather than a model of promoting the value of freedom for individuals. There will be compromising of freedom when morality is used to determine governance.
Freedom philosophy has the role of government domestic policy to be reserved to protection against fraud, pollution, and coercion. What do you see as government's legitimate role?