What is the meaning of [Better be the head of a dog than the tail of a lion]

Another old proverb says the same thing more clearly: ‘Better be the head of
the yeomanry than the tail of the gentry.’ In other words, it’s better to hold
a high position at a low level than the hold a low position at a high level.

> ‘They have thrown me out of the first team,’ said Fred, ‘and made me captain
of the second.’

> ‘You should be glad about that,’ smiled his friend. ‘Better be the head of a
dog than the tail of lion.’