Very hard if you don't follow the sport in question. Thought the Jack and Peter group were rabbits. Ah well. 2/10

Got the groups sorted in 22 seconds as no crossovers but, personally, i think the solutions need to be a bit broader. Australian test cricketers and English test cricketers are correct too. Put Shakespearean characters... not specific enough.

Somehow managed all four groups despite knowing next to nothing about cricket. I also guessed "rabbits" for the "Peter" group Orlando. A good grid, but could do with further refinement in the connections as FirstGofer says.