Why not light cruiser? That seems arbitary.
As for filling, again, no. When my swords, or in my chaos fleet, Iconoclasts Idolators, aren't protecting my batleship's rear, they are held back to finish off crippled enemy ships, to alow my dedicated gunship cruisers to get on with crippling more cruisers. You don't need a fully fledged cruiser to kill a crippled cruiser, its overkill. So escorts are perfect for this. But until they are needed, why expose them to fire they are not designed to face?
As for being shields, it depends on what era of history you are referring too. Anything up to WWII then you are incorrect. In WWII we start to see escorts used to defend capital ships against aircraft and submarines, a game mechanic that we can see in BFG. They were never designed to be amazing against hordes of aircraft, as there's only so much firepower you can put on an escort's hull.
But against incoming fire from other capital ships then again, no. Lets take the Bismark. The destroyers were never used to shield the RN cruisers from fire, they were used to fire torpedo salvos, before retreating to a safe distance. Who in their right mind uses escorts as a shield against capital ship fire?
Post WWII destroyers are used to be the main fleet aircraft defence. But BFG is not based on post WWII fleets but on wooden sailing ships, WWI and a little bit on WWII. Asking for escorts that are great at Aircraft defence will not fit the fundamental game mechanics.
Giving escorts greater power in any field will make them unbalanced. They are ok at what they do, be it torpedo runs for cobras, or gunship duty for swords. We have the firedagger for flak cover, and i'm sure if someone wanted to do it, an equivalent could be made for Chaos. They are relatively hard to shoot at the WB table. Other than that, I don't see the overwhelming need to make escorts any better.
As for escorts not being present in BFG fleets in the numbers they are in historical fleets, well, if you actually look at where the destroyers are in historical fleets I assure you they are not in the battle line being shot at! Lets take two well known examples:
Trafalgar- Frigates held back on both sides for scouting duties.
Jutland- Frigates held back to occasionally nip out and fire torpedoes and attack the opponent's escorts, and cover the flanks of the fleets against surprise attacks; leaving the capital ships to slug it out between themselves. E.G., Scheer's use of them to cover his retreat with torps. Which is perfectly feasible with 4 infidels in BFG.
So actually, historical fleets did use many frigates, but they were not seen in the main battle lines anywhere near as much as you imply. Therefore, few of them should be present actually on the table top in BFG, they have different roles.
So, I before trying to be an smart arse, don't say "thank you for proving my point", until I actually have.
