My personal opinion here if you are gonna test out any tactic you have to go from the start do the right things like play 5 - 7 friendly's minimum, train the positions ( if you are gonna play Hazard Wide target man then train him for it). I personally use Assistant manager for team talks i have an extreme liking for Jaap Stam as Assistant Manager for some reason.No i didnt, played friendly games with my own tactic, won all of them with big margin, also played first 3 games of regular season and again won all 3 with big margin. Then implemented your tactic and lose 2 in row.
Will start new save again only with your tactic ( u are good tactician so i think problem was in my approach and not in tactic )
Good luck with it man it should work out with Chelsea i see no reason for it not too if you do the right things before hand.