For an LCG idea of mine, it would seem more elegant and less confusing to place the faction icon on the back, the problem is that it reveal to the opponent that information.
My question is: Does it really matter?
If we take MTG for example, If I know that my opponent players has 3 white card, 2 green cards and 2 artifact in his hand, does it really influence the game?
It might even be interesting, it could be information that the opponent tries to deal with.
I thought that if the faction icon was placed in the right corner and players fanned their cards in the right order, only the top card of the hand would have a visible icon, plus the top of the deck. Still Players holding their cards differently would be disadvantaged.
It's not that it's essential for making the game playable, it's just that it could bring interesting features:
A. Bluffing: Players could think you have certain type of spell or creatures in your hand because you hold certain colors.
B. Targtting: Effects targetting cards in hand could make it easier to select which card to discard for example.
C. Prediction: If a player has a creature with protection from red, and you opponent has no red cards, he might be better to get rid of it.
D. Blind Drafting: You could draft blindly your deck at the beginning of the game by only knowing the colors you put in the deck but not knowing the content.
This is just a couple of ideas.