Following the footstep of Bartholemu, there is Opale. When Fimble knock at the door, Opale exclamate "Nice mansion. Generally, people living in these kind of house are too near there money for me... let's see what he has to suggest."
She follows the group as they enter the mansion.
"My name is Opale di Senzio, and I am arcanist, and not really interested in this job presently. Maybe if you are convincing, I may change idea, but I think at the number of arcanist around the table, you'll have all your need in magic.
And to carry something of value, it all depend. As you posted an announcement, I suppose that the rogues of the city have heard about it, so let's guess they already knows and plan to take what is yours. In that case, I suggest:
Two carriages to carry, your valuable put in a box. Another identicale box. You need the two wagons take different road, and make it one to be known, the false box. A lure for the rogues. The other group will travel incognito, I suggest to have some wheat or something, to pass the caravan as a simple farmer caravan, which mean there is a need to have commoner clothing for the second group. The lure should be some guards, and a few adventurers that looks good, just to make them think you have employ some adventurers to reinforce the rank of your men.
The skills mean a group that can act as guards, true gards are better, but anyone with a basic martial skill could play as a guard, and they should were the same uniform. The other group should have to play some paysan, which mean if an adventurer rely more on an heavy armor and a great sword to defend himself, he should better be on the first wagon.
So that would be the basic of a plan, but I still miss some information to make it more convincing. I think Anton has the same question in head. What the valuable, if you can tell us that information? Where the valuable must be taken and will have to go? Which are the routes betwen those two points? Have you heard any rumers of an attack on your valuable? Maybe with those information, my suggestion of plan will have no value..."