The same source says ten stacks to bring down a single MOAB. I wouldn't be surprised if they were saying that fourteen towers would bring down a ZOMG and all spawns. Unfortunately, the number isn't justified by anything there, so it's hard to say if there's any basis to it.
A ZOMG has 4000 health, compared to 700 for a BFB and 200 for a MOAB. That's 10,000 health for the MOAB-class bloons in a ZOMG (4000 + 4 * 700 + 4 * 4 * 200). It's not practical to think that four stacks of spikes would be enough to handle even the 3800 difference between a ZOMG and a regular MOAB, much less the 9800 to get a ZOMG down to ceramics.
A base spike factory creates five spike stacks. The Bigger Spikes upgrade increases that to ten spikes per stack. The MOAB-SHREDR upgrade does quadruple damage to MOAB-class bloons. That means that a 1/3 or better Spike Factory does 40 damage per stack to MOABs.
A base Bomb Tower does one damage to up to forty bloons in the blast radius. The Frag Bombs upgrade does up to eight more damage (total of nine if they all hit the same bloon). The Bigger Bombs upgrade increases the number of bloons that can be hit to fifty. MOAB maulers increase the base damage to ten and eighteen with Frag Bombs. A Monkey Fort (Monkey Village upgrade) doubles the pierce of the fragments. The maximum damage that a Bomb Tower under a Monkey Fort can do is
526 = (50 + 1) * 10 + 8 * (1 + 1)
That assumes that there are at least fifty-one MOABs in the blast radius and the blast only hits MOABs.
Note: it's possible that the missile tower upgrade changes some of these numbers. For example, the the 50 could increase. Unfortunately, I haven't been able to find any numbers on how much the missile tower upgrade changes things.