This strategy works much more consistently for me when fighting the Praetorian as Predator; it helps minimize exposure to the smaller aliens while making the most out of nearby explosives that one probably can. The specifics go as follows:
-Light shot the alien on the wall to knock it down/ possibly kill it so it doesn't interfere with upcoming charged shots (not sure what causes it to die vs just get knocked down)
-Light shot the gas canister the Praetorian is walking by (causes large damage to it without knocking it down, causing it to charge at the player)
-Charge shot the Praetorian once it gets near (damages it, knocks it down, and blows up the gas can on the ground near the corner of the tower to the right on spawn causing even more damage)
-Charge shot the rest of the energy bar into the Praetorian while moving toward the exit (damages it severely and also places it between the player and the aliens coming from behind, likely killing them with the splash damage if they get too close)
-If not dead, throw the Smart Disk at it to finish it off (keep track of its health, if still too high stay close enough to follow up with light attacks to quickly finish it off)
-Immediately jump up to the exit trying to avoid charge jumps
Few notes are I'm not completely sure if hitting the Praetorian in different spots deals different amounts of damage. It may be placebo but I feel like aiming charges shots lower by its legs deals more damage. The Smart Disk seems to deal between barely any to most of its remaining health, and I know that it deals different amounts of damage to marines depending where you hit them so it's probably the same here. Also the Plasma Caster cannot lock onto Xenomorphs when viewing in thermal vision so it makes quickly shooting the gas canister really easy. I'd also suggest the alien vision for swatting away the first alien since it's jumping/ attacking right at the beginning in the dark so I found it pretty hard to track without highlighting it. Also when moving past the Praetorian charge shotting it jumping allows for faster movement that's also way less likely to get interrupted by any aliens that catch up.