You definately can#t have the same tactics for home and away.
I am still tinkering trying to find a solution to the away game mystery. The effects from home games to away games in FM is unrealistic at the moment.....seems that you can create the same amount of chances away from home as you do at home but scoring does not occur at anywhere near the same levels. I just had an away game with 59% possession, 14 attaempts on goal 0 on target. It was boring watching it as I knew every shot was going to be blasted over the bar.
Basically make sure your away formation is counter attacking in set up. Keep it defensive, don't commit too many forward. Your away setup needs to be able to create fewer chances that are better quality. If you go gungho you might win a couple of games but in the end I will guarantee that the goals will dry up. I have just finished a season with the follwing stats.
Home - W13 D0 L0 F35 A3
Away - W6 D3 L4 F14 A11
IMO to much of a swing home and away in the game. At the moment it feels like turning a tap on and off. Win 5-0 home, lose 2-0 away and then you can win 6-0 at home. Pattern seems to repeat itself through out a season.