Hummus rich well drained soil is a suggestion, assuming you are planting in your garden, not a container. You will get great results in your container with either of Al's mixes. Al

So would "Hummus rich" be more of a description of fertilization rather than a descriptor of soil composition?

Hummus is the result of vegetative matter in the soil being broken down by the micro organisms in the soil. In the ground it often eliminates the use of any fertilizers. Its use in containers is limited or eliminated, as it has a generally negative effect on drainage. In containers it is replaced by synthetic, or chemical fertilizers, in most cases, which are ready to use by the plant, and do not require the micro organisms to convert to a useable state for the plant to use. Al