A couple of thoughts on this (untested)...
Place an extra block inside the bottom row so it's 2 thick. Zombies normally target a weaker point, so may be more likely to target the higher block this way. You could also put a floor layer that is at the same level as the bottom wall row so they have to climb up one to get in. I think either option would prevent them from crawling through.
They did update it to target the higher block more often, but it won't do it every time, so something like what I suggested may help with that.
I think that is probably the the most sensible and amicable resolution, I've read so far.
Players have spent years, finding ways to spoof the AI, floating bases, force field blocks,
placing furniture in the path; using sand bags, adobe blocks, stacking dirt 3 blocks high,
and the
Pièce de résistance planting immense fields of Cacti as a perimeter to prick the
zombies to death. They have sacrificed tons of digital trees, stroking keyboard keys discussing
it, again years invested.
Win win, Players would win, and TFP would win for not having to create a new animation
ai combo to thwart it. That is unless, it caused them to dig all of the dirt from under the
bases causing the whole thing to collapse. Hey, "
Stranger Things" have happened.
To paraphrase that crazy frigging droid M3gan
"Yoooouuuuu've....got......2
Ack-Cent-Tchu-8 the Positives
Ee-Lemon-8 the Negatives"