Demo too Full game (tactics)

I am currently very frustrated I used the demo to perfect a tactic for Shrewsbury town.

half way through the season i was 3rd doing very well but more importantly the team was playing just how i wanted them too.

so i save the tactic a use it on the full game and its not the same at all I'm being dominated home and away.

for example my demo tactic i had decent possession quite a lot especially home games but on the full game i was beaten 2-0 by Plymouth

and they had nearly 72% possession most of the time.

now i seem to be completely lost i can't think how i can change my tactic to get back to how it was because i have no base to start with i start with

its difficult to explain but i can't understand how or where to start!

has this happened to anyone else i always knew that there was a chance it would not be the same but i can't really understand why its the same principle!

maybe i should just keep trying until i find the right mix again but that could take ages lol

just wanted thoughts really.