There is a certain order of movement of the project forward.
Everything will be done according to the plan,
but, we can make adjustments to the plan, but not changing it, but only complementing it.
Thus, we will take into account the wishes of investors, and carrying out the plan.
This is all obvious.
After all, if you make changes to the basic development plan of the project - it may not coincide with the original plan, and accordingly the initial calculations of feasibility.
Here I agree with you. If the project development plan has been drawn up correctly and clearly, then there is no point in changing it even at the request of investors. After all, suggestions made may not always be useful for the project.