I disagree about the Sharonan ability to defend a 1000 mile supply line between portals (and they are very lucky that the longest gap between portals on the direct route is the 1430 miles in Failcham, 3 or 4 thousand miles would probably be beyond them). To see why Sharona can do this we first need to recall Arcana's limitations.
Arcana has no long range spells that can do serious damage to fortifications nor do they have bombs. This may change in the future and it isn't absolutely certain but given the following facts I think we can count on it for now.
1) The Andaran Scouts did not have grenades at Fallen Timbers. They would have been really useful so if they had them we would have seen them. That we didn't see them shows they didn't have them. That they didn't have grenades makes it just about certain Arcana doesn't possess them, why wouldn't an elite light infantry unit have grenades with them?
2) Despite the fact that we Arcanans routinely carry Sarkolis through portals, everyone from the most junior officer to one of their best researchers was dumbfounded and shocked by the idea of using a physical projectile to carry a weapon through a portal. That despite two centuries of thinking about how to attack a portal it hadn't occurred to anyone to shoot Sarkolis through the portal and have spells activate on the other side shows that launching Sarkolis through the air and having spells activate after you release it very very difficult.
3) The spell engineer who set the demo spell in the assault on Fort Salby was killed by falling debris. Surely if the Arcanans could set it off from a greater distance they would have developed a way to do so by now.
4) The dragon that attacked the bunker at the swamp portal did no damage with its fireball. I don’t expect it a battle dragon’s fireball or lightning bolt to do more than cosmetic damage to a railroad line either.
What the above means is that the only way for Arcana’s troops to damage a railroad track is to stand on it and use a crowbar or stand on it to cast a spell. That takes time and leaves them exposed to Sharonan attack. So in order to protect a 1000 mile rail line what Sharona has to do is dominate the entire rail line by fire. Shrapnel shells will kill anyone trying to damage track without damaging the track themselves. Here is what I believe Sharona needs to dominate a 1000 mile rail line by fire.
Small artillery forts, with maybe 10-15 guns and 200 men every five miles along the track. That distance is based on ranges for World War I artillery. Its general range seems to have been 10,000 yards or 5.5 miles. If Weber wants to make it easier for Sharona he can say that the existence of distance viewers led to an arms race regarding artillery range, which is what I would expect would happen, and as a result Sharonan guns are significantly longer ranged then comparative Earth weapons. But I will use five miles because we can be certain of that range. So to cover 1000 miles they need 200 forts or 40,000 men. In addition I would expect them to need another 2,500 men every 500 miles to serve as reaction forces to drive the Arcanan’s off the track if they decide to seize a long section of it. So 10,000 more. Total force 50,000. That equals about 5 divisions. My original post said Sharona might be able to support as many as 9 divisions at the front by the time they are ready to attack in the spring. If that isn’t wildly optimistic they can provide this defense.
Could Arcana use its mobility advantage to concentrate forces, punch out one of these forts and tear up some track? Yes, but they would launch the entire attack and tear up the track while under fire from the neighboring forts and within several hours the reaction forces would come up and drive them off and I expect the track to be repaired within 24 hours. That brief of a delay won’t interfere with the Sharonan advance (they certainly won’t be using just in time delivery!) and I would expect Arcanan losses to be heavy, which they can’t afford.
tonyz wrote:One thing to keep in mind here: worlds are very big places. The Sharonians have the advantage in portal combat (artillery can go through portals, spells cannot) and at other chokepoints due to their superior firepower.
Arcanans have the advantage of mobility and airpower, which is HUGE. Ironically, they'd be better off picking one world to fight in and just raiding Sharonian supply lines throughout it. Sharona can't begin to support enough troops to completely hold a supply line against Arcanan raiders (it'd be like Sherman against Nathan Forrest, only with Sherman having a lot fewer troops and Forrest being able to fly, and not much in the way of handy-dandy local plantations to seize supplies from.