its really depennds on how you want your strikers to do i would use adebayor and vela as an example..
i use an standard arsenal 442 formation
i normally play adebayor as the TM(target man) i dont use him to get me goals i get him to create a whole load for my other players including striker(vela) or my wingers(arshavin/guardado) or mabye fabregas bursting foward by holding up the ball, flicknig ball on for vela to chase, to do that you would play adeabyor as target man and play him more attacking minded to vela making him way more foward getting him nearer to the opponents goal causing all sorts of problems for their defenders eg - flicking balls, holding ball up to wait for support from vela.
and you would play vela less attacking playing him a deeper role right between the lines midfield/defence making him a difficult target for the opponents defenders to mark and you would set him to run with ball/foward runs and depending what what ratings he has for 'flair' if its above 17+ or maybe 18 you would tick 'free role' making vela move all over the place through the middle/left flank/right flank everywhere causing trouble..
got really good success doing it that way..if you do it the other way round like adebayor less atacking minded and vela more attacking it doesnt work as effective. but if you want your target man to score goals then i wouldnt suggest you use my way..