Yes Favor should be a tactic to aim for, among many other tactics like aggro, control, vikings or card steal. Because with favor you gain access to extra free card draws. Then there have to be a drawback of gaining favor, otherwise its just OP. Like a netural minion with no text or function is naturally stronger than a minion with "protected, draw a card", if they cost the same mana. Otherwise the minion with something good on it would just be OP. So gaining favor must always come with a cost IMO. Like destroy one of your creatures, gain 5 favor. Or to play a weaker minion with "Gain 5 favor". To create a unique playstyle and synergies around favor. Not just handing out random favor for "doing good", it becomes very hard for the developers to make any sense around it then.