Yes, of course! To my knowledge, the creation and removal of ministries does require parliament approval in most parliamentary democracies, and I also prefer that this power is not held by a president alone (as in a purely presidential system). However, in such a presidential system, a president adding or removing ministries still reflects a change in the same branch of government, the executive branch. The process of reorganizing ministries per se is not problematic and actually required for an administration to remain functional and able to accommodate new/shifting tasks.