I forget who I replied to, but in my post a few pages back about "Lead with *Nova*, not Charge" as a reply to someone accidentally targeting a Banshee... this is what I meant.
I always say "Lead with Nova, not Charge" for Vanguards because it allows you to survey the situation before committing. This is not an anti-Banshee tactic... in fact, I *never* engage Banshees with Charge/Nova specifically because of their huge range on the OHKO.
For the Vanguard players, trust me... learn to break the habit of leading with Charge, and you CAN survive (and be the top scorer) on Gold. All too many Vanguards lead with Charge and it WILL get you killed. Remember, your main offensive weapon is NOVA, not Charge. Use Charge as your lifesaver skill... and ONLY when you need it. It's easy to get into bad habits on Bronze, but to use the class effectively lead with NOVA.
What does this mean? Just run up to the enemies. Leading with Nova means if you see an immediate threat to survival you didn't see initially (Turret, Banshee, too many enemies, etc.), then you can Charge to get your shields back so you can book it out of there. Lead with Nova, use melee/weapon to pick off stragglers, reserve Charge for the critical moments. Learning to use Charge to *save your life* instead of offense takes some work, but you WILL become a better Vanguard player.
Also, sidenote on the Banshees: their barriers DO dictate the range of their OHKO. I've been pulled in then released (but the banshee still alive) when my teammates dropped her barriers before I got skewered. This means you can Charge/Nova once her barriers are dropped, but *not* before.