We put in a few hundred pin oak last year in the shrub strips, they were all 12"-18". Got them in right before a nice rain and ended up with maybe a 95% success rate and all of them doubled in sized and have branched nice. They are planted into some young native grasses and weeds that help hide them some.
We didn't protect any of them, the deer have nipped a few at the tops so they could end up more bushy than the others but I'm fine with that. It wasn't practical for us to try and protect them with the volume of trees we put out last spring.