Main different between Readying an action and Delaying is that by Readying you ready a specific action in reaction to a trigger whereas Delaying only makes you skip your turn to move it before or after another's.
Readying happens during someone's turn.
Within the party there is no point, but although it should technically be possible to delay to act between the actions of two wolvos, as you figured, it really wouldn't work so well since they are more or less all acting in no specific order, just as we do.