Playing older Round Based Games?

[Enakan]

Can you build and play games using old tabletop game systems?

The reason I ask is I must've missed the "round" base area for army design.

Like if I wanted to play stuff like Hordes, Malifeaux, All Quiet on the Martian Front, Starship Troopers, etc.

Should I assume if both players know the rules, they could play older games too? These are mainly skirmish scale games, smaller scales.

How would I build round bases?

Thanks!