I have a lean-to green house south facing the brick wall being to the north side. Even with minimum sun that wall takes in heat and gives it back at night, the green house went below freezing for the first time this year and it has been up nearly thirty.
I had a one foot high base wall on the south side as I have gravel beds and glass would have been a problem right to ground level.
You will find your dwarf wall will also take in heat and give it back, will stop accidents with ground level glass and some pots need shade so the wall provides it. Tomato pots behind a wall will stay moist yet the plants get all the light they want so to sum up more ticks for a wall than against, I would have it.
One more thought if you wanted a raised bed in the greenhouse, you already have three sides some wood boarding on the front side and fill it with soil, one raised bed for tomato's or anything you wish, just remember to change some of the soil each future year.