Although Queen Isabel does not have an army strong enough to confront the Royal Army, if she can resolve the problems of Prime Minister Prim and Duke Serrano, it would greatly increase the chances of the coup's success.
With the lingering influence of the Bourbon family, coupled with the efforts of numerous nobles, it might be possible to stabilize the situation within the chaotic Spanish Government after the loss of Prime Minister Prim and Duke Serrano.
Even if Carlo notices and returns to Spain, it will be difficult for him to regain control of the situation. After all, Carlo is an Italian, and some Spanish nobles still harbor resentment against him.
Moreover, Prime Minister Prim's agricultural reforms threaten the interests of the nobles, exacerbating their rejection of Carlo.
There are no issues when the Spanish situation is stable, but if Spain falls into chaos, whether the nobles will heed Carlo's commands is uncertain.
