Tatic is ok against shittier teams but since it's a control type tactic it'll mean that strong teams will rape you.
I always get destroyed in the CL with Ajax.
FM 15 is broken.
You can have the best team in the world with the best keeper in the world included and you will still lose a significant amount of matches because of unrealistic dumb goals.
Stick to FM14,most fun and most balanced engine.