I didn’t see this example, and I have little interest in discussing a broadly defined scenario in which you may assume as many conditions as you please to get the conclusion you want*. Especially since pretty much every anarcho-capitalist treatise addresses the issue of aggressive tycoons. An oil magnate may want to claim the power of eminent domain and seize his neighbor’s territory, but he - and the parties which aid him - risks the ire of the rest of society. Courts that sanction his action risk severe damage to their reputation. These considerations should not be underestimated. Maybe the oil magnate will feel the costs are worth it, and maybe he’ll succeed. The oil magnate Saddam Hussein thought he could get away with claiming the inferior Kuwait as his own, and he might have succeeded, too.
This is a problem with hypothetical scenarios: there is a tendency to ignore the actors’ long run considerations. It is all too easy to think of the scenario as a one-off game and not an indefinitely repeated game, in which your oil magnate has to consider the long-run consequences of his actions. More importantly, you pretty much entirely ignore the dynamism of society. If rich men claiming eminent domain is a pervasive problem, the masses (including the rich) have an incentive to develop mechanisms to inhibit such action in the future. Institutions and practices change to address the problem, just as they change should a new piece of technology make theft easier to accomplish. Perhaps the oil magnate succeeds today, but he may find that it is more costly to do it again next year. In five or ten years, he may see it impracticable to run roughshod over property rights, as the rest of society has caught up to his methods.
*The scenario is also incoherent: you said companies A and B are of equal standing, so why does company B suddenly have superior firepower?
Well I see that as completely backward, and I’m not sure what either of us could do to convince the other.
There is no contradiction. You are simply letting your sloppy language confuse you.