To paraphrase a great American President, "It's the synapses, stupid!".
Okay, so maybe he really, really wanted to get Americans to vote for him, and so he was being a bit dramatic, but the principle is the same. Sometimes, people just get hung up looking at the wrong thing, and need to be redirected.
First, a simplistic primer. A nerve (brain) cell has one neuron (output) but many dendrites (inputs). The cell 'fires' a signal down it's neuron, and where that neuron crosses a dendrite from another cell, a new connection, or synapse, is formed. This synapse transfers the signal from one cell to another, neuron to dendrite. The more interconnections between cells, the greater is the brain's 'understanding' of the world.These synapses can be excitatory (cause the cell to fire) or inhibitory (prevent the cell from firing).
Brain learning is primarily a result of new synapses forming from experience, and brain processing is a function of the number of synapses. For instance, there maybe a 'mother's face' cell, but it is just a cell until the cell dendrites connect with the visual neurons and get trained to recognize that particular face. The more synapses, the more this cell connects to other cells, and the greater the accuracy of recognition. It's like recognizing a face from a 100 pixel photo and from a 16 megapixel photo.The more the child sees its mother, the more synapses that form, and the greater the accuracy of recognition. One 'mother's face' cell, one 'mother's face' neuron, but thousands of synapses, results in greater resolution.
So the more dendrites that flow into a cell, the more interconnections (synapses) with other cells that can be made, the more accurate the perception. Instead of just connecting to the visual system, for example, the 'mother's face' cell can get inputs from the tactile, olfactory, hearing, and motion sensory systems. But the more neurons the brain has, then the more cells these sensory dendrites can connect with, and the more 'nodes of recognition'- that is, mother's face, father's face, brother's face, uncle's face.
The TL:DR, in very over-simplified terms, is that the fewer the neurons (cells) the less you can know, but the greater the dendrites, the better and more accurately you can know it. But without thousands of synapses forming from experience between all of the dendrites and neurons, you know nothing. Like a baby fresh from the womb.
But here is a fun fact. The more we learn, and the older we get, the more cells and neurons we lose, but the more synapses that are formed between what we have left. It seems that fewer neurons but a plethora of connections between them enhances our intelligence. Just like in a digital camera, more pixels per picture produces greater resolution but reduces the total number of pictures you can store on the memory card.
And perhaps that is the final answer - more dendrites, fewer neurons means greater resolution, but less 'breadth'. But in the balance, it is all about the number of synapses. In a paradoxical way, the less we can know but the more detail we can know about it.
See, for instance, https://human-memory.net/brain-neurons-synapses/