Your explanation for the Green group was that they where all Chancellors of the Exchequer. It should read were, not where.
I was disappointed to be marked incorrect for stating that the purple group were Prime Ministers. Likewise, when I guessed that the red group were foreign heads of state. That was marked incorrect and I should have said they are leaders of world countries. For heaven's sake.

"heads of state" marked as incorrect?

it's weird that some have first name and some don't -- made it easier to spot some but also the UK themed stuff was too tough

Prime ministers and heads of state are not usually the same thing, eg The Queen is our head of state. In most democratic countries this would be a president or constitutional monarch.
Churchill group a bit obscure, and could equally have contained John Major.

Thanks. A bit one dimensional. PMs not Oxbridge educated, rather too obscure.