Brazil has historically treated Guyana as a satrap of its own regional control. And there's a very real possibility that the Brazilian military dictates the terms to Lula, as they've already had their share of coups. So its more an Exxon-affiliated military commander working on behalf of Western economic interests to undercut Maduro's influence in their zone.

I also really don't think Venezuelans are interested in open war with a much larger and richer neighbor, for precisely the same reasons a lot of Ukrainians had no interest in fucking with Russia. Setting aside the ideological politics of the area, this would be a bloodbath for all involved and would undercut any hope of a unified Latin America. The divide-and-conquer imperialist strategy is the biggest weapon westerners have on their side when dealing with the Global South.

A single, unified South America would operate as a counterweight on par with the US, China, and Russia. These border wars are essential in keeping that future from happening.