While Prim was focused on implementing reforms and Spain was quite stable domestically, Carlo was surprised to find himself with nothing to do.
Let Prim handle the reforms since it's bound to offend people.
To be blunt, the reforms have offended all of Spain's factions, except for the Reform Faction that supports them.
If it weren't for Prim's exceptionally high prestige in the Spanish Army, it's likely the Prime Minister of Spain would have been replaced before his reforms were even complete.
The current reforms are also a huge gamble for Prim himself. If he wins the bet, Spain has hope of regaining its place among the great powers, and Prim remains a beloved Prime Minister in Spain.
But if he fails, those offended by Prim will not let him go. Even if Carlo could provide protection for Prim personally, his reputation would be tarnished, used as a lesson against reformists.
