You can almost always have another surgery--but what can be achieved and what has to be done depends on a number of issues.
The surgeon performing your next operation needs to be aware that the circulation is not what it was originally. This is one of the reasons that I believe and teach that that closed rhinoplasty, which allows the surgeon to limit dissection and never close a wound under tension, is much safer than open rhinoplasty for revisions. Data supports my beliefs. Soft tissue loss can occur when the circulation is not normal, but almost never happens after closed rhinoplasty. Even the best open rhinoplasty surgeons have healing problems on occasion.
It is also important that you and the surgeon have a well-defined and achievable goal, and that you have evidence (from photographs) that the surgeon has done your type of correction before, and that you like the results.
In your case, two reductions have not improved you because you need both dorsal and tip grafts to shape your skin--it cannot shrink to the shape that you want. Assuming that you want a straight profile and a smaller lower nose, that strategy will definitely work, but must be performed by a surgeon experienced in the techniques--that you trust. Good luck!