Giving them all the same starting wallet is a bad idea; they will start out with the same keys, but will eventually each generate their own, so their balances will drift out of sync.
In theory everything should work out, but in practice using the same wallet on multiple machines hasn't been tested much (I fixed a couple of bugs in the last couple of weeks related to a wallet shared between machines).
So before cloning, delete the wallet.dat (assuming it has no bitcoins in it) and let the clones automatically generate a new wallet the first time they start.