Large frame for camping fly

I'm in the process of assembling a frame for a fly for base camping/car camping etc;
Being sick and tired of those cheap fibreglass poles breaking I invested in some 12mm Easton pole sections and some angle joiners.
Half from TPT [ the BLACK] and the others from ANSCO [the GOLD] about 2400 wide and 2400 tall.
All 26 inch [ 660mm] sections so far.
I'm wondering if I need to replace the black centre section of the roof pole with a shorter length, either by purchasing new sections or by cutting the centre sections in half.
I have enough pole sections and angle joiners to make 3 sets of poles and hoping that I can set these at 1200mm spacing to suit the fly I have. So is what I have OK or will it be better with a more narrow top.
There is not much difference between a shorter standard length of 18" and the 26" existing but there is a reasonably large difference between 26" and 13"
There will be webbing or tape joining the three pole sets to take the longitudinal strain, possibly three sets at the apex and the joiners and some suitable way of joining the fly to the frame, probably Velcro tape. Also possibly be able to use shade cloth
I'd appreciate thoughts and feedback
Being sick and tired of those cheap fibreglass poles breaking I invested in some 12mm Easton pole sections and some angle joiners.
Half from TPT [ the BLACK] and the others from ANSCO [the GOLD] about 2400 wide and 2400 tall.
All 26 inch [ 660mm] sections so far.
I'm wondering if I need to replace the black centre section of the roof pole with a shorter length, either by purchasing new sections or by cutting the centre sections in half.
I have enough pole sections and angle joiners to make 3 sets of poles and hoping that I can set these at 1200mm spacing to suit the fly I have. So is what I have OK or will it be better with a more narrow top.
There is not much difference between a shorter standard length of 18" and the 26" existing but there is a reasonably large difference between 26" and 13"
There will be webbing or tape joining the three pole sets to take the longitudinal strain, possibly three sets at the apex and the joiners and some suitable way of joining the fly to the frame, probably Velcro tape. Also possibly be able to use shade cloth
I'd appreciate thoughts and feedback