I think you're saying that a descending join from dead side is OK, and I've often thought about this one. However, I've figured that with an overhead join, you're meant to be able to read the signal square, safely above circuit height. If you don't then it isn't an overhead rejoin.
Typically when I return to my home field from the south, I normally call up 10 miles out. If the radio operator is working and lets me know it is "25 right hand" then I'll descend to circuit height cross the departure end (upwind)of the runway at circuit height and turn onto downwind (deadside join I think is the technical name
). Of course doing this I am aware of people joining from different directions and would normally make sure I join behind someone already on downwind .
My reasoning behind this is that say you were approaching from the North and I from the south for an OHJ, you would be crossing the downwind end of the runway 1000' or so above circuit height, and I would be crossing the upwind end at 1000' above circuit height, which would only put < 700m between us at the same altitude. I then have to make another turn to cross the downwind end of the runway, again 1000' above circuit height before comencing a descending turn to cross the upwind end at circuit height.
To me this seems a lot of low level manouvering with potential conflicts with other traffic when there is really no need. Obviously if the radio operator is not there or there is any descrepancy about which runway to use then I'd overfly the field first.
To reverse the scenario if I were in your shoes approaching from the North for an OHJ, and someone else were approaching from the south in the manner I just described, I would commence my descending turn so I slotted in behind them...
However there is no excuse to actually join on a proper cross wind as this could cause all sorts of potential conflicts, with people departing, people already in the circuit and people joining the circuit.
Cheers