LA Marignon Questions

[Kobal2]

Well the thing is, blood nations never have enough slaves (even when they're pulling 400+ a turn) and they're especially vulnerable to jokers teleporting in to say hi.

Regular nations can always use one more fort of course, but there's a point where they're already maxxed out on mage recruitment per turn, at which point additional forts become token defence which is not really needed as such : they won't die out even if they lose a 5+ gem province or two (or ten) for one turn, then take them back the turn after.
The same disruption really messes up blood nations however - either their hunters get killed, or they just flee but won't be able to hunt the turn they move back in, and even assuming the raiders are dealt with they'll have left a heap of unrest behind which further delays blood hunting.

Basically, in the late game a raid is a mere one turn's income disruption for a regular nation ; but at least 2, more likely 3 turns' for a blood nation. Which is why fortifications are even more appreciated than usual.

[Shangrila00]

Well, I'll point out that Mari's Goetic Masters can natively cast Hellfire, Leech, Life for a Life, and Infernal Prison, with the last 2 admittedly a lot of research with limited reward seeing as how Mari has little reason to summon anything other than Fallen Angels. If you know how the enemy is going to raid, there's very little your blood hunters can't stop short of a full sized army except maybe Earthquake/Rain of Stones by a lifeless caster. (I can't think of any, are there?) Oddly enough, the removal of SDRs has signicantly weakened raiding on bloodhunters, since no longer are most hunters defenseless B1s carrying SDRs.

It probably ends up a matter of preference though, fortifying your own territory vs. using extra gems for more offensive punch.

[P3D]

Keep in mind that against some nations, the Royal guards are
less useful. Against Gath they are useless. If you had the misfortune to meet them early, rush Blood research to get Blood Boil.