Replacement or not?

As much as arsene may have misguided us before about pod and giroud not being rvp replacements, I can understand if they were to now be his replacements now.
What I dont get is who is going to score the 30+ goals? Walcott scored only 13 goals in all games last season. Without van persies top form we would have come 6th or 7th.
If pod has a good first season I cant see him scoring 25+ goals. Bar one season 7 years ago he has never scored 18+ in a season because hes not that type of player. And if your thinking giroud, well we can only play one striker at a time, and im sure hes more of a backup, as a much better and willing option than chamack when needed.
What im trying to say is we need to buy a more prolific attacking player to help the rest of the attackers make up for rvps loss. I doubt gervinho will contribute heavily.