ah see that's why your entire perspective doesn't work. you need to assume you already know the afterplant positions. if you do then yes it really doesn't matter. but if you dont, the low hp player has no chance as soon as the tank dies. it isn't acting as a distraction. he's getting the info on the position of at least one of the players if not both so the full hp player can clutch. 1v2 with full hp is easier than a 1v1 with almost none.
if the low hp player waits truck while the other guy 'tanks' and he doesn't trade then the round is lost immediately. but if he takes the fight first then he can almost certainly let the tank trade off his death and play the 1v1 accordingly with the same amount of information but more hp. it 100% makes sense that the low hp goes first if they're coming from the same direction. just space appropriately.