Maybe this is even the main reason why there are scrimages (do not read: main reason scrimages are used for, but do read meant for)
My assertion was based on the following quote from the BB rules:
The primary purpose of a scrimmage is to give your team an extra day of training and experience, so try to schedule them every week, if possible.
Now, of course, they _are_ a way to try different tactics, though these will be limited due to the need to put specific players in specific training position. Also, they will never completely mimic competitive games due to the fact you can't use TIE/CT.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."