Hi @rentmoney I agree with you that the Reward Cards are handed out to generously. I don't know exactly the timeline and player base numbers that are needed to calculate on how to distribute the new cards evenly over time. 
But from my feeling I would agree that the ratio between the lowest reward league Bronze 3 / 5 cards and Champion 1 / 150 cards = Ratio 30:1 is too high. What you are proposing is a Ratio of 15:1 that sounds more fair to me.
Like I said the correct amount of cards, if 1 or 3 or 5 for Bronze 3 league, thats what I really don't know. I hope that @yabapmatt and @aggroed are considering every aspect of there decision in regards to player base, timeline and overall gameplay experience to build a deck for new players.