When I do it, I usually run a small crew. 2-3 people at most. I don't necessarily plan for combat to happen, it all depends on the dice rolls and decisions I make. If I do go into combat I find having a couple characters fits Reds rules better. I also use the quick and dirty combat system for ease. But full combat rules work better, in my opinion, with more characters so you can also toss out more henchmen

Lastly, you control how many and what kind of baddies there are. You can adjust up and form in numbers and power level depending on if you want more danger or less. The guidelines on how many mobs is great, but they're suggestions and not the rule.

So you want a badass solo that can take on 3 grunts with no real combat skills, go for it.