Cross-divisional playoff (the classic 8 into 6)

[Ieuano]

Hi all,

I have two regional leagues (Cymru North/South), each with 3 relegation spots.

There are 4 regional divisions below that, whose champions promote automatically. The remaining two spots go to cross-divisional play off winners (i.e second place in South East vs South West to promote to South, and NE and NW to promote to N). In reality there are some stadium rules that might exclude an opponent but lets keep it simple to start!

I'm struggling to get this cross-divisional play off system to work. In a way this is quite similar to the German regional divisions if anyone is working on those?

Thanks everyone.