Evading like everything else is based on each situation, but most escorts make runs from behind, so speeding up to dodge them is the tactic that works best...if you're deep enough. I just do the few mild turns to get my sub out of the way of the rolloffs. Crew rating has great effect, escorts with elite ratings will drop more in front of you, harder to outrun them.
I've seldom ran out of battery using the flank sprint method, the danger comes more from taking battery or electric engine damage, really hard to evade when you can only go 2 kts...
Course many other factors come into play, sea state, thermals, etc...Have as many in your favor when you attack....and always a full battery
Yea, most DD's are pushovers, the escorts are the pain, but a few DD's do carry Y guns. Seems the stock amount is 40 per rack. I can't recall what file, have you tried the sea file for the ship type, think it would be in one of those folders.