Blitzcrank when his intended target is untargetable

When blitz's furthest target from him is either an assassin, or zephyred, he walks up to the nearest enemy to auto and then pulls the furthest enemy from that point. he doesnt retarget the second furthest but targetable person.

similar issue with melee or short range champions like graves where they target the nearest person but if they cant get in range for their autos, they just sit there instead of pathing to the secondary target that is attack-able. Champions need to have a secondary nearest target so the dont fkn stand or hold their ability.