@Denise , I like your idea to co-train the pups at the same time and would just recommend switching handlers midway. Also, training one at a time is a great idea, allotting a portion of the lesson to each pup.
As litter mates growing up together, I think it’s incredibly important that they engage in activities without one another, whether that be training, yard time, play time, quality time with pet parent, crating in separate locations, etc. It’s too easy for them to hyper-bond to one another and then — potentially — have a hard time coping when they must be inevitably separated.
Are they same sex, or opposite?
They are ADORABLE!