That's not how it works because odds 1.2 is not a sure win.
I can't understand the logic of playing multi-betting on odds at 1.2. You expect to win because of the odds, not because you know how those teams performed.
But if that your preferred style of betting, and if it works for you, then good.
1.20 odds usually win but if you parlay it with 1.20, you will only get 1.44 which is still low or less than 50% of what you will get when you win. Therefore, I find this method hard to win in the long run as two bets compared to one, one bet is easier to win. In addition, it's important to understand that oddsmaker knows the probability in every odds they'll make and it should always favor on the sportsbook.
If you want to multi-bet on very low odds like 1.20 it is better if you make it more than 2 bets. With only two bets, the odds would still remain low just like your example.
What do you mean by oddsmaker always favoring sportsbooks? Sportsbooks don't have a house edge unlike other casino games. With sports betting you don't beat the house. The betting site always wins because in every match they will receive a certain amount from the loser.