When browsing clan stats and clan activity stats i see two different figures for current season info on number of games, ratings and stuff. How come?

i think it adds up all of the members individual stats

well I asked everyone I could to came up with a name for "Activity stats".

The activity stats is actually: Clans, Communities and Countries stats BASED on the single leagues.
For example:
When you play in the single league. Lets say you played a team17.
Same amounts of point you gain will be added to your clan activity stats.
Same will be added to your country activity stats and same for your communities if any.

So if you are viewing CKC clan activity stats, You are actually viewing how CKC clan members did in that specified period of time. (In the single league)