do Exalted lords get the benifits of exalted champion aswell? and can you only have 1 model on the board with exalted champion/lords or is it just 1 class of models and you can still have a squad?

do Exalted lords get the benifits of exalted champion aswell? and can you only have 1 model on the board with exalted champion/lords or is it just 1 class of models and you can still have a squad?