If land is subsidised then it will tend to be owned by fewer and fewer people

Excessive land ownership is unjustifiable.

We can justify property ownership on pragmatic grounds, it is effective to own what we make because that way we retain the incentive to create. It is also effective to own a certain amount of land because if we have our own plot, we will better take care of the land.

If we seek the right to exclude others from the use of land or property, we must at least have a justification without such we are simply being aggressive when the land is defended, or threats are made for defence. It is aggressive to 'defend' land if we own an excess.

We should not be able to (it is immoral and aggressive to) protect land if we own an excess. There is no reason to defend an excess of land, it is not a vital and justifiable use of force and not descalating the situation. The State could seize land that is owned by someone with an excess and sell it into the market, which would allow others to live more freely. The property could be expropriated via either eminent domain or compulsory purchase.

If the Government expropriated land from those who own an excess, in violation of the Lockean proviso then land would be (able to be) more efficiently used. Land inequality might lead to (result in) land expropriation, which might be seen as theft.

There is a natural tendency for land and wealth to cluster (and accumulate) into the hands of a small number of people. If someone owns a lot of a rentable property such as land it is easy for them to acquire more because their living costs will always be below their aggregate rent income. Land tends to be owned by fewer and fewer people, as time progresses.