You can definitely get King Tomato seeds from Krakka + Jute, had a plot that was 4 Krakka, 4 Jute, using 3 Shroud Soils and 1 Thanalan Soil on the Krakka Root, and the Than Soil one gave me King Tomato. Also got King Tomato from Krakka between 2 Broombushes, and King Tomato from Krakka between 1 Broombush and 1 Jute.
The only times I've ever got King Tomatos is from Thanalan soil, the Shroud soils have given me nothing special (other than the 9 extra Krakka Root).
