Good insights IMO. I remember they (fleet dev) used to do 15-20 yr market and network development scenarios, with a range of different fleet compositions and see how they work out, to get an idea on flexibility, adaptability of the different options. The last scenario I saw included a possible MD11 stretch, so a while ago
But I imagine they still have this simulations approach.
I think the 737-10 vs A321NEO business case will be a very interesting one for KLM. Those aircraft offer KLM capability they don't have at this stage but fits there network very well. If it becomes A321, it surely will have LEAPS, GE and KLM/AF have strong JV's.
In my opinion, I think this AF/KL narrow body procurement will be Airbus' to lose. While KL currently flies B737NG's, they probably aren't predisposed to buy to the MAX. True, there were some recent uncoordinated procurements in the alliance (the A220's for AF & the E195E2's for KL), but I think this time the two allied companies will want the same fleet type for their larger narrow body aircraft needs to achieve better economies of scale. And in my opinion, the A32XNEO line probably best meets their needs in terms of capacities, range and "carbon friendliness".
While Airbus is making odd noises about not needing to be overly-competitive in the narrow body range due to Boeing's troubles, the AF/KL procurement is an important order for the EU to keep "in house". There is EU prestige at stake, plus jobs to be protected/added, which means there will be considerable political pressure for AF/KL to award this order to Airbus.
They are not Lufthansa Group, where LHG orders the a/c for LH, OS, LX, EW, … and where they all have the same interior etc. They are not IAG which ordered the XLR and distributed it to EN and IB. They never were that much of a group apart from not competing with each other. I think, it would be clever for them to use synergy effects. But I don’t think that they will really start with that with this order. Maybe in the future, when capacity is needed and they want a „replacement“ for their A380, B77W and 744. They could order either 779 or A35K, for both airlines. But not now.
Interesting that you mention IAG as an example of group buying. It has been about 2 years since Willie Walsh announced a MOU with Boeing for 200~250 MAX'es, yet nothing has happened since then. The A321N-XLR's haven't even reached certification, much less deliveries (which may be in 2023), so EN and IB are still waiting and things may change in the meantime. The biggest member of IAG, BA has only partial fleet commonality with their smaller siblings and there has been no group ordering to start to correct that. Also, Brexit has hampered the practical application of the synergies that were expected when IAG was first formed.
As for LH Group, it consists of LH acquiring a hodge-podge of smaller EU airlines, all of whom were struggling financially even in the good times. Since the acquisitions, there is still much work for LH Group to do to rationalize these (mostly-aging) fleets. The parent group did order some B77W's for LX to replace part of their aging A340 fleet and they also arranged for the purchase of A220's to replace LX's odd-ball regional jet fleet, but to my knowledge, that has been the extent of it, so far.
So I guess that the AF/KL alliance appears to have the same operational similarities and issues of these two competing groups.