I've spent years looking for a coverall maths formula, the books and white papers don't really tell you much in that respect,for example they certainly don't explain why HOME teams with a WWD record win a higher % of games compared to a team who've went WWW.
Poisson as portrayed in books is a big huge red herring, every book or expert will tell you that poisson under estimates the draw, not true, it under estimates some and it over estimates others, it just under estimates more.
It might be different with an all singing and dancing stats program but it's not as easy as I thought it would be, I must have done my 10000 hours by now.
Mind you I think I'm seeking perfection when it doesn't exist across all leagues.