Well, that would require the Decepticons to think a long way around their standard operating procedure, for them to make contact with the Shawsheen without being bitten in half on the spot, to actually find something the Shawsheen want badly enough that they're willing to go and look for and find and dig up Starscream, and then for the Shawsheen to not go back on the deal, take the 'cons stuff and bite them in half.