Let's Discuss Zombie Weaknesses and Counters

It's a well known part of the meta and gameplay as a whole in the franchise that certain Zombies have certain Plants that are meant to counter them, and vice-versa. This is mainly about the Zombie side, however.

This came to mind when the Pigeon Feeder Zombie and Zombie Pigeons are supposedly countered by Spikeweed (and to an extent, its direct Merges, Sawgrass and Chainsaw Grass), but in action, Zombie Pigeons easily obliterate Spikeweed due to their sheer numbers, and Pigeon Feeder Zombie quickly summoning more of them. If anything, it would make more sense if Lychee was stated to be their counter, mainly because it's a Wall Plant, and deals sufficient damage around itself when attacked, even by a small amount. I'd like to add that Lychee can also counter the newly refurbished Flapjack Zombie, since it attacks Plants in its adjacent lanes, Lychee can not only stall it from another lane, but deals damage back in a 3x3 area, thus pairing well with Buzz Choy.