The initial set of plans looks like a very high level program design, which is appropriate for this stage of planning. It is also going to be up to the constituent member nations to get this built, which is consistent with a continental system that is being planned.
This is a good beginning to a long term solution, but the costs may outweigh the benefits in the short and medium terms.
I hope that the first segments chosen are those that add the most value immediately, then expansions radiate from there so that the incomplete segments are still valuable in their smaller parts. Since they are defining technology now, the different parts should integrate easily into one large system.
My concern with picking China is that Chinese engineers are likely going to go with the expensive option no matter what; they’ve done it in China a lot and I don’t see them changing.