With a population of 804,567 and an active "army" of 4600 active personnel and 3000 reserves (2 brigades)

Compared to a country with a population of 28.2 million with an army of 115,000

Even if they conscript 1% of their population (in the short term) that's only another 2 brigades

Do you think their society will have the morale to fight as though the US invaded them with a Latin American neighbour? To me it seems that the many leftists in Guyana would be apathetic.