Those numbers in that example are return rates.. Based on 1 dollar.. A ml fav would be a number less than 2, fwiw..
Regarding units, it will pay in the long run to make all bets the same amount (one unit), whatever your unit amount may be.. Your unit amount should be 1-2.5% of bankroll (as stated earlier), but the same every time. When your bankroll increases 50%, your unit amount will change (but still the same %).. Hope this helps..