I think even Lewandowski would have struggled to make an impact in this side over the last two matches. To be fair to Moore, he has put away the two chances he's had, albeit one of them being disallowed.
Once Wales have rediscovered their fluency, there are enough potential goalscorers in the team for the absence of a world class striker not to be an issue. At present, it is the way Giggs has set up the team to play that is preventing them being a high scoring outfit, not the current players being profligate in front of goal.