I'm not sure if it is this Tropico that I played or not but I do know that I absolutely loved it. There were a few broken mechanics such as the uselessness of your military during invasions but for the most part this is forgivable and perhaps was a statement on the developers that if you want to be an overlord dictator, you need a lot of soldiers in order to maintain your position.
I return to this game on a regular basis an enjoy just playing it on "endless mode" as well.
You wont need an army if you manage to keep your approval above 60% with all factions, but the mechanics of the battles are still a little broken... sometimes one soldier will kill 5 rebels alone.. some times 1 rebel will kill 5 soldiers.. you never know what is comming lol