Quando eu estava digitando a pergunta, a resposta veio à minha memória.
Ents parecia ser bem democrático (aparentemente beirando o anarquismo na vida cotidiana) - eles tinham um conselho ( Entmoot ) onde o decisão sobre se ir para a guerra estava sendo feita. Eles respeitavam os líderes, mas aparentemente nenhum monarca tomava decisões - até Barbárvore teve que convencer outros Ents, apesar de ser o único "ancião" que estava ativo.
'Only three remain of the first Ents that walked in the woods before the Darkness: only myself, Fangorn, and Finglas and Fladrif – to give them their Elvish names...' {{I'm too hasty... so I skipped the rest of the quote with loooooooooong explanation of why he was the only one of the 3 elders dealing with the matter}}
... Still, I daresay I could get together a fair company of our younger folks – if I could make them understand the need: if I could rouse them: we are not a hasty folk. What a pity there are so few of us!'
... 'Hoo, eh? Entmoot?' said Treebeard, turning round. 'It is not a place, it is a gathering of Ents – which does not often happen nowadays. But I have managed to make a fair number promise to come. We shall meet in the place where we have always met: Derndingle Men call it. It is away south from here. We must be there before noon.'
E foi muito explícito que eles estavam decidindo juntos:
'...and after that we shall have to decide what to do. However, deciding what to do does not take Ents so long as going over all the facts and events that they have to make up their minds about.
(source: Lord of the Rings - The Two Towers, Chapter IV, Treebeard)