William, the duke of Normandy: 1048 to 1060

Count Hoel of Cornouailles is a popular figure, a worthy counter to Conan. By backing Hoel, you achieve a lever on the feelings of many Bretons favorable to Normandy. You can accomplish much, you discover, by never moving troops around at all: just the threat of what you could do is sufficient to sway many political decisions. By drawing Conan's attentions back home, his interference in Maine is almost totally eliminated.

You are able to deal with king Henry's attempts to besiege your border holdings. And by taking a few of his in return, you keep him occupied (honor-bound) to take them back.

Meanwhile, young Herbert is beleaguered by the Angevin house of count Geoffrey. You can appeal best to the Manceaux by:
Sending a powerful Norman army of occupation.
Betrothing your son Robert to Herbert's sister Margaret.