You mean 200GB, not 200MB, correct?
"increase performance in games "
At best, you'd get some reduction in level loading. Thats all.
In theory, you probably could do it.
But...
You'd need a full backup of both 2TB drives, in case things go wrong during this process.
You'd have to take into account where, exactly, these partitions are on the physical HDD. The outer portion or the inner portion. There can be a significant difference in read performance between the two.