Is this yeast starter appropriate for my 10g lager

[strongarm]

I have a 2l starter with a stir plate. My beer profile is
OG 1.067 and 10 Gallons, it's a Bock using WLP 833 lager yeast. Beersmith says I need

Yeast Cells Needed 919Billion
Yeast Cells with starter 379Billion

Also it says Yeast packs with starter 2....does that mean I should have put 2 yeast vials in my starter to get the 379Billion? It also recommends a 5.21 l starter size?

If I step this up after the first starter is done...say another 2l of wort (200g dme, 2l water) how would I calculate the yeast cells?

If I pitched with only half of the recommended yeast count will I have serious issues?

 

[Xpertskir]

use yeastcalc


Its way easier, especially for multi step starters.

 

[strongarm]

So it looks like I need to ramp it up to a 4l starter for my 2nd step to get over 900B, to do that would I just use 400g DME and 4l of water then decant and pitch my 1st starter into that? I don't think my stir plate could handle a 4l starter so I will probably have to shake or oxygenate. Also I don't have a 4l flask so I guess I could just use a 1g glass jug to get close to 4l.