A question rearding threats for encounter building

Hi all,

Im just mucking around teaching myself Vagabond as im considering running it for my son and his mates in the upcoming holidays and had a question around calculating threats as it relates to encounter balancing/building. (coming from 5e experience that im trying to not let bias how I look at this system!).

The threat block includes how many of a creature may appear. Does the threat level (roughly) cover all that typically appear or PER instance of each one. EG giant rat is threat level 1 but has 2d6 appear. For thepurpose of calculating a fight with my 2x lvl2 bois, and I roll a 9 should I treat that as a lvel 1 threat or 9x lvl 1?

(and yes I know environmental and party context etc all matter I just mean in general terms of how this system works.)

thanks in advance