I get your point, but it's not even close to saying take out RVP's goals because he has still had a couple of very good seasons.
And I'll admit I only mentioned Ayew because I'm a fan of his. He wouldn't really suit us at all as say we did get him Podolski would likely move into the hole behind RVP which while it would help in attack our midfield would constantly get outnumbered.
But Martin's only really come to the fore last season, because he was a late developer and had been knocking around in rubbish teams beforehand. It's no more harsh to discount all Van Persie's goals than it is to discount his assists.
Podolski would be a shocking hole player, I'd imagine. From what I hear, Ayew can play in the centre, but with those stats I quoted you earlier I'd be unwilling to trust him in such a pivotal role, particularly when it's not his favoured position.