[Verjigorm]

Well let's see.. Soul Contract is Const-2 so you're looking at 100 RP to get into it which is gonna be... (we'll go with 6RP/turn):

6 + 12 + 18 + 24 + 30 + 36 (Ding!) Turn 7

but you need B6F1 to make a Soul Contract, so going with someone fun like a FoB who has that by default, we could conceivably have a flying devil platform on turn 7 since we're going to patrol/hunt in our capitol with the fountain to make sure we get lots of slaves (this way I can concentrate my little mages on research and I can hire a diverse group).

So say that we have this little dude ready to go on turn 7... It'll now be 10 turns before our first Soul Contract is at capacity, or turn 17. That's without an LLP (which is 360 RP)

126 (Turn 7) + 42 + 48 + 54 + 60 + 66 Ding! (Turn 12)

So I forge my first LLP on Turn 12 and since I've got both of those contracts ready to go now, I can focus on something other than Const for awhile since I'm starting to get some mages and it'll be some time before my opponents get anything that can counter my Devil/Imp swarms.

I could go Thaumaturgy/Evocation to get some communion started (I find the later communions start the less lifespan they have since one Battlefield AoE spell foils them) or, if I'm kinda lonely in the blood nation realm, I think I'd go grab some Archdevils.

I am frequently thinking Arco, so I forget sometimes other people don't have AN mages... thus the Amphipteres.

The question then arises... Why put the Soul Contracts on the Jesters at all? They can't obviously go deep into enemy territory as a retreat would destroy the contracts, so they have to remain on the borders. You could send them with a roving Blood hunter team to act as a base where the Devils get collected en masse. That way instead of having the devils generate in individual pods:

1 Jester + 1-10 Devils + LLP

You would have 2-3 pods that look like this:

Blood Hunt group (3-4 Goetics/Diabolists),
Patrol Commander (Undead) with soul Contract
Any number of extra Soul Contract holders.

This protects the Soul Contracts, centralizes a "refueling" station for the rovers and provides a strong mobile defensive cluster for your advancing army, and as the devils form, they get used for patrolling.

This little way station can also build and defend the construction of fortifications in your border territories.

The idea I'm trying to project here is that you don't want to lose those Soul Contracts, and there is no reason to risk them. They should be kept at home and not brought into the field since they do not contribute any significant value to a field commander. A properly supplied army could reinforce itself without putting the Soul Contracts in the field.