It's not as much the number of engines, which troubled N-1. For example, when Soyuz launcher starts, it has 32 chambers - not engines - running simultaneously,

It's not as much the number of engines, which troubled N-1. For example, when Soyuz launcher starts, it has 32 chambers - not engines - running simultaneously, and it's a rather robust and reliable rocket. What was the probable reason is the lack of testing of the huge system of the first stage of N-1 all together - test stands required lots of money and also time, both were in short supply (N-1 is surprisingly a rather inexpensive rocket, in comparison, say, to a better flown Energiya). Engines on the first stage were also untested, by design - they were single-start engines, so they couldn't be tested on a test stand before actual launch. Both of these problems were taken into account when Energiya was developed. It had a huge "stand-start", both for testing and for launching, and engines were fully reusable, with the idea of later returning the first stage of the launcher (horizontal landing, with parachutes) and flying it again.