As others have said, you probably don't need that many warmups for DL unless it's sky high already (over 300+ in which case Starting Strength most likely isn't for you because you're not a beginner). Probably only 2-3 sets. If you're above 225 lbs start with 135 then 225 then your work set would probably work well (at least that's how I do it).
Metcon does depend on what kind of metcon. Something like Linda (aka 3 bars of death) before an SS is probably not a good idea while on the other hand something more running-wise might be easier with the squats the next day barring a severe case of DOMS. It's definitely doable though where you can bring yourself up to that level to do any type of GPP in between although you might feel a bit rundown going into that last strength workout a lot.
Mainly, it depends on your goals here. If you want the GPP or need the GPP then do that otherwise if you're weak and want to bring up your numbers fast then solely focus on strength and neglect GPP. Well, even one GPP and 3-4 strength workouts would will keep GPP relatively medium-high if you wanted to focus more on strength but a good GPP base.