innodb_buffer_pool_instances and innodb_buffer_pool_size

Let’s assume a 1.2GB innodb database.
AFAIK, it should fit totally in RAM, thus, at least 1.2GB for innodb_buffer_pool_size.
Then, if possible, we should set innodb_buffer_pool_instances to a value that innodb_buffer_pool_size / innodb_buffer_pool_instances is >= 1GB

This “chunk”, should be greater than the whole innodb database?
In other words, as per my example, should I set the following:

innodb_buffer_pool_size = 2G
innodb_buffer_pool_instances = 2

(each chunk will be 1GB, lower than innodb database size)


innodb_buffer_pool_size = 4G
innodb_buffer_pool_instances = 2

so that each chunk would be 2GB, greater than innodb database?