Why would Odo bring greater compassion to the Great Link? He's not particularly compassionate. He's not really much different from the rest of the changelings, in fact. He seeks "justice", which isn't much different from the changeling-wide desire for order, in fact, it's pretty much the same thing. Odo wants "Justice", but only justice that he sees as such. If there's any exchange of views, it would be that Odo would end up being overwhelmed by the Great Link's view of Solids. It is far more likely that Odo would come around to their way of thinking, rather than bringing them to his way.