Sounds good. We'll probably want several barracks towns eventually, fortunately there's a lot of good terrain up north.
A 4-turn settler factory can operate at size 3.0-5.0 (that is, from size 3, 10 food in the box to size 5, 10 food in the box) as follows
turn 1: work cow, wines, bonus grass -> +5 food, 6 shields
turn 2: work cow, wines, bonus grass, and forest on growth -> +5 food, 8 shields
turn 3: work cow, wines, bonus grass, normal grass -> +5 food, 7 shields
turn 4: work cow, wines, bonus grass, normal grass, and forest on growth -> +5 food, 9 shields.
Total: 6+8+7+9 = 30 shields = 1 settler.
For this we need to mine one more grass tile.