cook time for two breasts

[allornothing]

I'm cooking two breast this thanksgiving, one an 11lb and the other a 9lber, I figure I will put the smaller one on the bottom rack.  My question is on cook time do I figure 10 minutes per pound for each bird or do I add the weights up,  20lbs and due 10 minutes which would be 200 minutes versus 110 for the biggest breast.   I will cook to temp, but I'm trying to get a ballpark time so I know when to start everything else. 

[sliding_billy]

Separate cuts, separate calculations.  The only thing you need to worry about is the impact on pity temps when adding more meat.