In ground, I find it really doesn't matter how early I plant, the plants sit and pout until the soil warms up before they take off. I have considered trying to heat the soil with black plastic prior to planting.
Good idea to plant horizontally to the surface where the soil will be warmer.
Those planted in containers grow more quickly for me due to the soil warming up faster because of the black container surface. I also plant the tomatoes low in the containers and fill in dirt as the plants grow. That way if there is a frost, the plants are sheltered by the containers and can be covered easily if needed.