Suppose there are many species living in the same but stressful environment. The environment is very stressful and pressures whole populations to conform and adapt to the environment. Now, in making phylogenetic trees, one rule of thumb to take is the law of parsimony. In such a stressful environment that drives so many species to fill specific niches in the environment, do you think that the law of parsimony may be more hypothetical and less practical in this example? Or, perhaps, such an example cannot happen in reality, because reality has constraints?
My point is that in the field of biology, biologists have to balance the theoretical/hypothetical and the practical. For example, the biological species concept is a very strong hypothetical concept, but it has practical limitations. Likewise, the morphological species concept is a very strong practical concept, but it has hypothetical/theoretical limitations. So, the goal for biologists is to find the balance between the hypothetical and the practical, which is the tricky part.