Your point would maybe have been valid if Tomkins hadn't played full back for England for the last two years and at Wigan for longer than that so he is sticking to his word about a settled squad, we have plenty of 'match winners' in there and with Sinfield we have an outstanding leader and organiser, yes Brough would have been a great addition but by no means does England's chances rest on him being in the squad.
McNamara had been doing exactly what you are asking for he has been working since he was appointed to get a settled squad by looking to the future, that 'future' is now the present and we have a fantastic looking squad. It looks like Widdop may be fit which adds to our options in the half back role, we have some excellent 3/4s and the forwards look very strong indeed.