You asked about a logic to sequentially enable stations. So my posting is off-topic.
From your map screenshot of the facility I deduct that it is a reloading complex or transfer site. Trains bring ores from mines there and other trains pick up ores there to bring them to the 60 spm complexes. Am I correct with this deduction?
I use reloading complexes a lot for big factories. They make sense as logical single point of entry of a resource into the base. But, depending on desired throughput, they can be big bastards. The usual approach is to implement M unloading stations and N loading stations, where M>=N and a big balancer and maybe a buffer inbetween. Therefore I find your approach of pairs of unloading and loading stations quite interesting and actually
very smart. It completely ommits the big balancer, can ommit all buffers if desired, it has almost the same throughput as in a M=N setup and (BIG PLUS!) it can be scaled (a reloading complex following the usual approach can only be rebuilt for a higher throughput), by adding more pairs and enlarging the stackers.
The only thing that 1:1 reloading can not handle at all is to balance wagon load in case the trains to be unloaded come unblanced.
AND, I think for a 1:1 reloading complex with X pairs, there does not have to be any intra-pair dependencies, like the sequential activation you asked about. How? You only need to ommit the inter-pair buffers. And set up an inter-pair circuit controller for de-/activation of the loading station. (And with a bit more of inter-pair circuit logic you also can have inter-pair buffers).
How in detail? All unloading stations have the same name and all loading stations have the same name. A train to be unloaded can chose among any of the free unloading stations. When it entered and is ready for unloading, the associated loading station is activated. Any train to be loaded will enter that loading station. If none is available the train to be unloaded has to wait. The throughput is slightly lower than in a M=N setup in the usual approach, because the transfer has to wait for the train to be loaded to move from the stacker to the loading station. Also the stacker for the trains to be loaded need circuit controlled rail signalling for the case when all of the loading stations are deactivated.
In case inter-pair buffering is required, the condition for a loading station to be active just shifts from "train to be unloaded present" to "buffer contents > 0". And the condition for a unloading station to be active shifts from no condition to "buffer contents = 0".
After writign all this, do you still need sequential activation of stations?
If yes, maybe you are planing for one pair of stations to be associated with a specific 60 SPM complex? And by sequential activation you want to distribute resources evenly to these complexes? Then you probably want that, because you don't want to have a half full train sitting at a 60 SPM complex, while others are without resources. And you want the buffers for times when there are more resources than demand. That is the only explanation I can come up with, for your requirement.
In case that is your intention, how about this general idea for balancing:
viewtopic.php?t=67235
BUT think of the chests being the buffers of the reloading station pairs, and the unloading stations being the inserters, which insert into the chests.
The resulting behavior would be this: In case all the buffers between station pairs are empty, it does not matter to which 60 SPM complex the resources are shipped, they are starved on inputs anyways and always the first one is as good as all of them in a sequence. But if resources start stacking up in the buffers, only those unloading stations are activated, where the inter-pair buffers contents is lower than the average in all the inter-pair buffers. Thus ensuring an even distribution among the pairs and hence the 60 spm complexes. It only requires one combinator per pair of reloading stations and one math combinator for all reloading pairs. It easily upscales by adding more pairs of stations and setting the divisor in the math combinator to the total number of pairs.
Would that solve your problem? I am pretty sure the solution to what you want underneath is one of these two suggestions. And each one is simpler and more robust than sequential activation.