Hyboria/Fantasy Rules for a HS Audience

[nickdives]

I was wondering how the "combine all the health points of bases grouped together" thing works in practice?

Very well, we used casualty markers so that when a combined unit loses a baseworth, a base is removed.

A recent small game with Conan defeated the evil To-Me-Kupa and his hordes.

[DivisMal]

That’s a great looking game! 

[Bodvoc]

'I was wondering how the "combine all the health points of bases grouped together" thing works in practice?'

You create units from 2-4 bases (or companies as they are known in the rules). Each company has a 'Resolve' value, for example a Formed Company has a resolve of 4, thus a unit of 3x Formed Companies has a total resolve of 12. We use counters to keep score of loss of resolve.
At the price, it is very hard to find a better system than Fantastic battles and I have tried lots.