No sir, the problem with using video guides is getting dependant on them (to them?), if you know your units, you can replace almost any line-up you see in a video. If you have weaker tanks and the video places the healers later on the map, try placing yours earlier; replace one duelist with another, most times than not a bandit can do the same work as a valk against magic attackers when 1-on-1 situations etc etc
The point is to think outside the box and use the guides as just that, guides to follow and improve, not instructions that need to be obeyed to the letter
This same thing happened to me when i was first starting and watched videos because i was too weak to clear things, but then i was too weak to fulfill the video's units level or roles.