Yes, these sorts of threads introducing new units need to be very well thought through and explained fully. If the idea is taken forwards, SC development team would test the unit and tweak the stats for balance purposes (but they always seem to start out OP), but you still need to give us a good idea of what you mean by "large housing space and training cost".
Moreover, these sorts of threads need to be presented well with a good layout to it (split it into sections or something) to catch peoples eye.
