"grounded in either" is correct and usable in written English.
You can use it when making a comparison between two things, and you want to express that either of the two things could serve as a basis for the comparison. For example, you could say: "The argument was grounded in either economic or moral principles."
If defenders of abortion rights largely abjure the "thick" substantive case, grounded in either foetal non-personhood or the primacy of maternal rights, in favour of the liberal pluralist approach, the first-order metaphysical stance of abortion opponents who have certainly not stopped pressing their own "thick" views may become more prevalent and, indeed, come to seem all but uncontested.
This good fit is practically useful, but intellectually not very satisfactory, because the familiar or Forward Weibull distribution is a purely empirical construct and there have seemed to be no reasons, grounded in either atmospheric physics or probability theory, why wind speeds should conform to this model.
The argument that the presence of 10,000 or so American advisers was an important variable in the equation is poorly grounded in either logic or on-the-ground realities.
The data presented in this paper suggest that such social interactions were grounded in either altruism or stigma.
Since the rock's physical state transitions that map onto the NOT gate's computational state transitions are not grounded in either the causal or dispositional properties of the rock and its states, the rock does not implement the NOT gate according to the causal and dispositional accounts.
According to Cartesian-style foundationalism, in order to count as justified, a belief must either be grounded in other justified beliefs, or derive its justification from some special status, like infallibility, incorrigibility, or indubitability.
Without it, some crews will either be grounded in a crisis -- or will fly with increased risk.
If there are no such descriptions available, then every rigid designator for a concrete object may be said to be "broadly" causally grounded in the respect that it is either grounded in the primary way by means of ostension to an object in something like a causal baptismal ceremony or it is hooked to a description some terms in which are causally grounded in the primary way.
Yet he pledged no boots on the ground in either country, and just 475 more American troops to supply, train and assist the Iraqi and Kurdish forces.
"It is the first responsibility of any government to ensure the security of its people and to be prepared to defend our nation from those who would do us harm, so we are right to be offering air support to the government of Iraq in trying to defeat Isil/Daesh, but let me be clear, we do not want British boots on the ground in either Iraq or Syria.
On the ground in either Iraq or Afghanistan, this string of words would prove a less-than-meaningful constraint.
