How can a group of mutually distrustful nodes agree on the same ledger? No worries—the class academic rep has the answer:
Classic BFT protocols require the total number of nodes to be at least three times the number of malicious nodes, plus one. In other words, fewer than one-third of the nodes can be malicious.
BFT-style consensus requires multiple rounds of voting communication between nodes. The more validators there are, the more messages need to be exchanged, so there is often a limit on how many validators can participate directly in consensus.
You only understand after learning the hard way: read the manual first.
$ATOM 1.747 (+1.93%)

Just my personal opinion—take it with a grain of salt. This is not advice.