Craig, the poster of this thread, passed away recently.Craig?
You're essentially relying on your lower order to be able to come in and hit from the off and always get a quick score. It doesn't always happen. Each batsman has a responsibility to be posting more than 200 in 40 overs.
200 in 40 overs is a joke and the sort of rationale that helped the likes of England look horrendous in the WC2011.
We are on about individual batsmen, aren't we?
That's kind of the middle order's job - Eoin Morgan, MS Dhoni, AB de Villiers et al. have made a career of it.
And we have to remember as well, strike rate isn't static across a batsman's innings. Ali Cook, for example, has scored at ~90 per hundred balls since his return - but England's scores after 10-15 overs haven't represented that (and Bell/KP score pretty quick too). They recognise that striking at 70-ish is acceptable to get set, and then you can force forwards to score at a higher rate - rotating the strike becomes easier, and the boundaries become more frequent. If Bell, KP or Cook ton up in an ODI, they rarely take longer that 110 balls.
Trott bats within himself, and is an anchor for the rest of the team - it lets the likes of Morgan show up and hit out from ball one, and he rarely 'hogs' the strike. He isn't taking up 4 or 5 balls an over blocking, he gives the strike to the faster scorer. More importantly, he ensures that he stays there, allowing the other batsman to bat without fear of a collapse. Sure, he may only strike at 75, but he'll be facing less balls and allowing the other batsman greater freedom.
Plus if Morgan falls, he can bat with Bresnan, Broad and Swann, rather than having to let them do it themselves.