Early Grouping games hard, medium, or difficult?

[BYUgrad06]

So I have started to go though the grouping games and decided to start with the first ones Tests 2-10, expecting them to be less challenging compared to the later ones.  I struggled with coming up with effective setups, making several attempts and had a difficult time with the inferences as well, especially on the Lizards, Snakes, Gerbils and Hamsters game.   I've been going through the LGB, but it leaves much to be desired in the way of grouping games.  There's gotta be some general principles in approaching Grouping game setups, no?  These games weren't covered by the PS setups guide, so I was left to guess on my own.  Some ove the rules in from the games (Tests 5, 6, 8 and such) seemed convoluted and confusing, and I found it difficult to make inferences. What do I do? 

[BYUgrad06]

Thank You Very Much.  I was just frustrated at the beginning of the games, because I was stumped about how to effectively set up the variable sets and make inferences.  If I was Dustin Hoffman's Rainman I wouldn't be worried, but I went through the LG Bible and the Setups guide and have found no general principles in approaching the setting up of the grouping games. On the Hamster?Gerbil/Lizard/Snake game I tried the numberical distributions but was dumbfounded on how many distributions to make and and how to use it in making inferences.  Again youre imput was appreciated.