Primeiro, junte a tabela de pontuação, trocando o time da casa com o time visitante e trocando a contagem de gols. Isso fornece alguns dados de origem que são facilmente agregados e a consulta para gerar o cartão de pontuação é algo assim:
select
team,
count(*) played,
count(case when goalsfor > goalsagainst then 1 end) wins,
count(case when goalsagainst> goalsfor then 1 end) lost,
count(case when goalsfor = goalsagainst then 1 end) draws,
sum(goalsfor) goalsfor,
sum(goalsagainst) goalsagainst,
sum(goalsfor) - sum(goalsagainst) goal_diff,
sum(
case when goalsfor > goalsagainst then 3 else 0 end
+ case when goalsfor = goalsagainst then 1 else 0 end
) score
from (
select hometeam team, goalsfor, goalsagainst from scores
union all
select awayteam, goalsagainst, goalsfor from scores
) a
group by team
order by score desc, goal_diff desc;