As this graph shows doubling the amount of neurons improves the accuracy of the networks and provides about 100 Elo each time. The smallest network however with just one neuron is essentially a Piece-Square-Table, not even a tapered one. It provides only the most rudimentary evaluation for a position.

I think now there are three ways for humans to reduce the playing strength and I would like to invite you to combine them and try a match against him and tell me how that felt compared to e.g. the weak bots on chess.com. (I'm sadly only a 600 Elo player myself)
If you want to give it a try download Leorik 3.1 from github then replace the network that came with the downloaded version with one of the smallest networks (maybe start with 1-Neuron even) and when you setup the engine for play in your GUI set the UCI option Temperature to 100-200 (which will give each root move a random bias in centipawns) and then limit the Nodes to ~20000 in the time control settings. Now it should play always instantly while you can give yourself a larger time budget! Let me know if you found Leorik fun to play and how changing the three parameters influenced his style.
(without any of the modifications Leorik is around ~3400 Elo)