ihr deutsch ist schrecklich = your german is terrible - terrible in a scary way, both of you
du hast glueck, clan = you have luck, clan - first person, informal, out of wack
haben sie gluck, clan = have luck, clan - addresses the group
viel gluck = much luck - much easier
viel gluck mit euer clan = much luck with your clan - probably perfect
the word 'viel' directly translates to 'much' but is used exactly as we would use 'good' in the situation
these sentences would be comprehended in pretty much the same arrangements in both english and german... so 'you have luck, clan' sounds just as stupid in german as it does in english. there are surely other good ways to convey the message as well.
