Soil Order Distinction Question

There are multiple questions in the past exams where a soil will have an Ah layer thicker than 10 cm which should classify it as a Chernozemic soil. There is also a present thick Bt horizon as well, which should classify it as Luvisolic. In the answering key for soil orders in the lab manual, it indicates that a soil should be classified as chernozemic before luvisolic, but according to the problem, this site is within a forest (versus grasslands where chernozems should be present). It seems like the proper answer should be Luvisol in this case but I am confused as to whether the soil order classification key on page 79 of the lab manual is something which should be followed considering it causes some contradiction in this question.

You have to be careful about making a decision about soil order only based on the presence of the Ah horizon that is thicker than 10 cm. Many soil types will have such Ah horizon, but not every Ah horizon thicker than 10 cm is the Chernozemic Ah. The Chernozemic Ah horizon needs to fulfill ALL of the following criteria: to be thicker than 10 cm, to be present in a soil located in a semi-arid to arid climatic zone in a (natural) grassland ecosystem, to have C/N <17, to have Ca2+ ion as the dominant ion on exchange complex, and to have base saturation >80%.