To a degree. Take part 4 and 5 of the Shroud. Healing is usually determined by the lowest HP total. So if you have 100 hp less than all the other melees, then you, all by your lonesome, are causing the cleric to use sp at a higher rate.
Now.. usually there's someone under 300 hp, so it's probably not the case.
Standing behind Harry is a valid strategy in part 5 as well. My pure rogue employs it as well (about 375 hp). But.. one thing to keep in mind is that you need 3-4 static people to 'hold' him in. Those guys can't simply shift because they happen to have aggro, or Harry could run off. So while it may be a totally valid strategy to stay behind Harry... it's only made valid by those 450-550 hp guys that are taking the brunt for ya.