"Client diversity is directly incentivized by the Beacon Chain's reward and penalty protocols. Single-client dominance is a hidden threat to Ethereum, invisible while the dominant client behaves faultlessly but potentially catastrophic when a consensus bug rears its head. Having multiple clients is a unique strength of Ethereum and a testament to the diligence of the developer community. However, that good work is undermined when one client controls a majority of the stake. The ideal scenario is equal distribution of staked ether across at least 4 clients, giving a maximum of 1/4 of the staked ether to each client. This is easily possible with the production-ready clients available today."