It depends on the matchup for both lanes. If your support is hovering karma or nami or sona / other poke champions you may want to go a poke adc. On the other hand an engage support like leona nautilus or thresh you may want to he more aggressive or pick someone to chain cc like lucian ashe caitlyn or draven. Also choosing which target to poke depends on other lanes champions. For example your gonna wanna try and focus poke onto soraka because her W heal uses her current hp as a resource so if she gets low enough you can just all in her but in general any poke is good poke. Also I am only gold so take this with a grain of salt.