If Chara/Grizz both can't go Game 5 and they decide to dress 7D (Kampfer + one of the young LDs), why not dress the best player? Urho is likely the most talented of the 3 (Urho, Zboril, Lauzon). If the point of Kampfer is the experienced veteran they can play if the rookie struggles, it doesn't really make sense then to argue against Urho citing his lack of experience. Play the best player, in this case Urho, and if he struggles you can use Kampfer.
That said I really hope at least Griz can go, they clearly miss his puck-moving abilities.