Probably problem at squad level leadership in FDF is that while corporals (and some times sergeants) who lead the infantry squads have gone through ~112 days long reserve NCO course, on other hand assistant squad leaders, who leads squad's four+ man assault element if situation warrants it and takes charge of squad if squad leader is absent or has fallen, is given no leadership training. Squad leader picks ASS.SL from one of 6 month rank-and-file guys appointed to his squad after basic training and at begining of specialisation training period (AIT? MOS?). Althought 4 months is propably long enough of time go through all squad members to choose for proper ASS.SL. Also proper attitude might compensate any deficiencies in training.
Only exception to this are MOUT infatry companies of Guard's Jaeger Regiment and some special and "special" forces units that have NCO as assistant squad leader.

Also on infatry squad compositions.
That new 9-men squad type will be used in so called regiona battlegroups, which are given specific area to do defence and delay actions. Operative brigades and battle groups will still use "traditional" 7+/-1-men squad.

My first thoughts when I read about this new squad structure was "if they want use nine men squad divided to half-squads, they should copy us army squad with tweaking or if they want three teams they should copy USMC. Are these kinds of thoughts arrogant as served neither in US army or marines?

And I have never received any sort of officer or NCO training or led even team sized unit (Only expection was one voluntary MOUT course for reservists. On second day in each squad everyone acted as squad leader in turns. When it was my turn to lead assault I felt like was pushed into arctic sea)
Also how would I assemble 3x3 squad?
If only requirement is that it should be 3x3 I would go for
Squad leader, MG (PKM or LMG M62) rifleman (M72)
Team leader, MG (PKM or LMG M62) rifleman (M72)
Team leader, MG (PKM or LMG M62 rifleman (M72)
And best shot in squad is given scope

But if it has to be organized as command team, rifle team and MG team I would preferably go for
Command team: Squad leader, rifleman (with APILAS or MBT-LAW), rifleman(M72?)
Rifle team: Team leader, Designated marksman (either AR with rifle or dragunov), rifleman (with M72)
MG team: Team leader (with M72?), Machinegunner (PKM or LMG M62), and machine gunners assistant (withM72?)
...
Wall of text...
I hope my text makes sense.
More propably tomorrow. No I have to go sleep.