On Hit items, And Runes

I find it weird that things like grasp of the undying and Tiamat work on champions that have a range and melee attack, default to the melee attack for damage and on hit affected. such as Gankplank using his Q, to poke and use grasp of the dying, doing full damage and not the 40% it should be doing. as well as poppy shield attack being able to activate Tiamat and hydra items, as well as using the active item on Titanic Hydra to have a ranged cone attack. There may be other champs that have these but it's a weird interaction that doesn't fallow other champs such as Nar, being able to build any item melee or ranged, but it only activating when he is in mega or normal Nar respectively. IE Ruinas Hurricane on Normal Nar haveing additional projectiles, But mega Nar only getting the stats of the item and not the unique passive of additional projectiles.