The effects of Might of the Old Ways happen in the listed order, so the +2/+2 bonus happens before you check the powers of creatures you control. For example, if you control two 2/2 creatures and a 5/5 creatures, choosing one of the 2/2 creatures as the target will allow you to draw a card. Conversely, if you control a 1/1 creature, a 3/3 creature, and a 5/5 creature, targeting either of the two smaller creatures will not allow you to draw a card.