I agree that the Family Guy game poses no threat. Instead they are just trying back tail on the success of The Simpsons Tapped Out.
Also, remember, the Family Guy universe is not as big as The simpsons. So while it may attract players from this game, I guarantee that it'll be in no time that they will come back.
Any other game wether it be Family Guy, South Park, American Dad or whatever that tries to copy this formula is only a clone that wants in on the action and the success that TSTO has had since it's launch in 2012