CoreSet and small skirmish games?

Hello,

new player here. Just got the FWW Core box, went through the scenarios and would like to introduce this to my brother as a skirmish game that we could play against each other. I still do not get the wave system as it is a little bit confusing, will look to it later on but:

Question: Can I build a reasonably balanced small battle mode/skirmish forces out of the Core box or do I require to buy some more miniatures/cards? If it is possible, can someone give me a sugessted build for survivors and mutants just based on the Core box content? (I know about the app - but I failed so far to build balanced forces - so any already tried combination that work well would be appreciated)

Thank you!

I forget what exactly is contained in the core box, but have memories of doing pretty well with the Aviator and Brute working as a team. IIRC I gave the Aviator his cap and a Pipe Rifle, and the brute had a Sledge Hammer, Baseball Cap and two Frag Grenades.
Of course, this was before they stripped them all of their armor and changed all the point costs.