Protectorates broken?

[Cruelsader]

It turns out the critters were allied with everyone except other Romans and some factions on the other side of map from me. I have to give credit to the weasels and the Senate: a beautiful trap and I stepped right into it. I know it is all random but it seems like a plot of a mastermind:

1) The Senate is praising my conquest but growing fearful of my power. They strike a deal with Numidians who are down to one province.

2) Numidians ally themselves with all my neighbors and factions beyond them. Then the Senate asks to negotiate a protectorate with Numidia.

3) As a true Roman I dutifully obey only to discover that any further conquest is frustrated - I cannot attack any allies of my little pet kingdom without "betraying" those I have sworn to protect. My standing with plebs does not allow me to attack Rome.

4) The Senate has checked my power and Numidians have saved themselves from a certain destruction. Not speaking of swimming in cash - I had to grant 30 000 denarii to "convince" them to become a protectorate.

However, the Senate was too clever for its own good. Six turns later Britons achieved victory shaming Rome. Truth to be told I had completely forgotten about the victory conditions of a short campaign and was aiming for the seat of Emperor but ...well victory is victory. My first RTW defeat.