Agreed. Any A-frame pole set-up would need considerably stronger poles to give an equivalent strength to a centre pole.
I also have one of those old Polish Army tipi tents made out of two Polish Army canvas ponchos, buttoned together. This uses a centre pole. I rigged this up with either three or four poles instead, freeing up all of the very limited space inside. The poles were expandable washing line props and much stronger (and heavier and bulkier) than the centre pole provided with the tent initially.