One of the keys to playing a mono Jungo deck is to realize that you're not always playing to win. Rather, you're playing not to lose. Your opponent may directly do more damage to you than you do to him....but that doesn't mean anything as long as you've got the higher Life total at the end of the match. And ending the match with more Life than you started with is something Jungo's good at.
Jungo has some heavy hitters and is perfectly capable of pulling off 2HKOs with several combos. But don't always go looking for the 2HKO, because some of them are so obvious your opponent's probably seen them repeatedly before.
Poison with Sylth, or hit them hard (Askai, Bragh, Ongh, Scotty, Chill, Adler...) and then sit back and use damage reducers (Pegh or Niva) or life gainers (Kreen, Nyema, Scopica). Or use Nyema or Kreen with Fury to hit them hard and massively boost your life at the same time.
In something that's 'timed', like the Daily Tournaments, you want to get the match over quickly so you can move on to the next one. In ELO or Survivor, though? Take your time and don't always go for the obvious quick wins.