Qm said

[Xietor]

The fact is tramplers were given the low morale because they were not intended to fight to the death. In a way, adding high morale low cost infantry units to their group severely undermines the risk of having them turn on your own army. And it takes no great general to mix the units either.

Rather than raise their cost, and have them continue to fight to the death, I would think the more logical solution is to allow them to rout after they have received substantial damage, and trample their own troops.

That is the double edged sword of using the tramplers. No, I do not think you should be able to just raise the cost and continue to have 72 hp tramplers that fight to the death.