Plants that PvZ 3 could add

Fume shroom 4 sun medium range shoots fumes that pierces through zombies

hypno shroom  3 sun hypnotize the zombies that eat it

magnet shroom: 4 sun takes metal from zombies

Assorted pult: launches nuts and berries at zombies: 8 sun can attack in this lane and adjacent lanes launches a nut at the closest zombie dealing moderate damage and berries at three other zombies dealing splash damage

hurrikale: blows a chilling wind pushing back zombies 4 sun medium recharge 

cursed shroom 4 sun all zombies in a 3x5 area are weakened meaning they take extra damage from everything and deal less damage

fire pea 6 sun shoots flaming peas which does burning damage over time (does not go through armor)

toxic pea: 7 sun shoots toxic peas which damages zombies over time (goes through armor) 

dragonfruit pult; 8 launches dragonfruits that exploded into shards dealing decent damage

soul patch 8 sun: has a offensive and defensive mode 

offensive: punches zombies and slight knock back

defensive: does not attack and when another plant takes damage this takes damage instead 

Doom shroom: 7 sun destroys zombies in a 5x5 area and leaves behind a crater