On the par, No I'm the one outnumbering the CSA by a massive margin but this is on BG
I'm naughty in the fact that I cleanse the entire field of enemies though instead of finishing so the max they can field is 50K so my first corp actually out numbers them heavily.
Then i have 240 Napoleons, 70 20 PDRS, 60 30 Siege and 30 Whits - this is the reason you play Union I guess - most of them are sent running before they even get a chance to fire back xD
Regarding Salem:- I think the only way is to do it like supply run - take the point then lure them all away from it or do it last second a cheesy tactic though
On a balance side of things I admit every battle after Shiloh was pretty trivial but on the other hand everything before and including Shiloh was quite the nasty nightmare.
When I tried the MG run of Phillipi the battle timer was a lie - It ended with 2 hours to go - which left me rather red faced failing the first mission X_X
For both sides I've played on BG and both times after Shiloh my army simply begins to out number the opposing forces - this usually happened in vanilla but since I actually now can take a far larger majority in it benefits me far more.
Side note: After playing some MG i can see why you don't make your brigades so large. started with a 4000 1star and 1800 2star and went against 6 x 1700's won it but wanted to see how bad I had scaled it so I restarted and split the 4000 into 2 2000's and became vs 6 x 1300's. so 2400 less infantry.
Probably best to have Recon 2 so you can play the scaling game in MG I guess :x