I think Dalinar simply isn't as far along as Kal. His spren hasn't manifested at all, for example. If my theory is correct, you have to reach a certain level of bonding before you can formalize it with the Oath.
BTW, another point on the Ideals, better explained using Shallan as the example. When Shallan takes the Second Oath of Truth (the second ideal of her order), I think she will be always assumed to be acting truthfully, thus enabling her to Soulcast without having to reveal a new truth each time. Like the Second Oath locks the bond in the position that it goes to when she speaks a truth.
Finally, something I just noticed. Kaldin's Second Oath binds him to "protect those who cannot protect themselves". Well, one of the Windrunner Attributes is protection.