Two oscillators sound bigger than one
Two waves slightly out of tune drift against each other, and the sound gets wider and richer.
Osc B adds a second wave and Fine detunes it from Osc A. Unison goes further: it stacks copies of Osc A, each a little out of tune.
Your turn. A slow pad envelope is already in place. Add Osc B and Unison to make it as wide as the target.