My 2 cents worth (since I can't design scenery and destroyable objects) would be to include in the Typhoon Campaign some missions attacking rail targets. Wolfi made a nice German Br50 freight loco/tender along with what we Yanks call a Box car (goods wagon?) and a Tank car (for petrol/oil) as well as a flat car without a load (maybe someone could put a destroyable tank on it as well and a FLAK car that will tear your shorts off!!!
Someone (not me, 'cause I'm a pothole!) would need to create destroyable trackage (I have some nice pics of HO track with ties and roadbed in sections) that can be incorporated into the scenery as destroyable objects for the train to "run on". It wouldn't really run on the track ... I envision somehow matching the track "position values" to the train's "position values" much the way that ships operate on the water. Am I making sense here?
How to make the train? If you were to envision the engine/tender and the cars that follow as a series of small ships moving in column you get the idea. Or you could have 3-4-5 cars together as a "ship" with each being destroyable (or at least being able to smoke,burn,explode) and put 4 or 5 of these "groups " together to make up the train.
I have not worked out how you would destroy car #5 of 20 and have the engine/tender and other 4 cars still being able to move while cars #6 thru #20 remain stopped on the tracks. Nor have I figuered out how you stop the 20 cars when you destroy the engine/tender. (WAAAY beyond my pay grade)
Realism? Well, with grouped ships, anything but straight trackage would not look realistic (it would with individual cars). But remember, any Civil engineer will tell you that when building a railroad, rule #1 is FLAT, #2 is STRAIGHT ... unless you have to go through a mountain or over something like a river. Curves and elevation changes cost money and should be avoided whenever possible.
To my mind, most of Europe is flat-ish (I know, it's a generalization, but bear with me) ... thus you can fly into a section of a mission and there is the roadbed, running from point "A" to point "B" (wherever the hell that might be). And after a while ... there's the train ... just "sailing" along (maybe with some smoke and steam???) Gentlemen ... there's your target!
Some effects that are needed would be that MASSIVE release of steam when the fighter's bullets open up the boiler (we've ALL seen that gun camera footage) as well as that box car (goods wagon) that DETONATES
in a MASSIVE BLAST (we've all seen that one as well) .
I won't go into attacking railyards (the pics I have are straight, curved, left and right turnout sections so you could use various combinations to create "freight yard ladder tracks" ) ... but that is easily within reach.
ENOUGH ALREADY!