I don't think you are doing anything wrong. I'd say it'll take a good week to see if the longer PM nap is going to work and then another week to tweak the A times YK?
Starting with J, his naps were pretty good. So he did
Wake up 5.30?? (4 hours A time??)
Nap 9.45 (40 minutes)
Wake up 10.25 (2 hours 45 a time)
Nap 1.10 (1.5 hours)
Wake 2.40 (4 hours a time)
Bed 6.40
Woke 11.15/ NF 1.40/ wake up 4.55- resettled 5.50
I think that first NW was likely OT. I think you are heading in the right direction. Do you think they are on the higher ends of A times? Id stick to similar today but I do wonder if he'll need 3 hours after the short nap and hopefully that'll make the nap longer than 1.5 hours. But hold fire with that just yet.
Now the rascal H
Wake up 5.30

(4 hours A time)
Nap 9.45 (1 hour)
Wake 10.45 (2h35 A time)
Nap 1.20 (40 minutes)
Wake 2.00 (4h20 A time)
Bed 6.20
NF 2.45
Wake up 5.30
I think that PM nap was UT after the hour am nap. I always found mine could practicslly do a whole A time after an hour as opposed to J who needed a bit less with only 40 minutes. I think it's fine he does an hour nap but I'd push that next A time out to 3 hours to make sure he's not UT. Pretty fab night. Well done H!!!
I think honestly on the whole they are actually doing well. I appreciate though with both you could be up a lot. I think though the solution lies in you and DH splitting the nights. I think one of you needs to head on to bed early and get a decent sleep from 9 and then do from 4am onwards and the other one does the NWs and NFs. And swap the next night so at least every other night you are both getting 8/9 hours sleep before needing to be up at 5am. I just think the babies are being babies and I fear you are going to drive yourself mad tweaking routines trying to get them to sleep better than they are capable of at the minute. I do think the longer PM nap should help the OT at night and they'll keep having good nights like H did last night. My BIL and SILs twins are a similar age and still having 1 NF. I know they say they would be divorced if they didn't get a decent nights sleep every other night and what I'm suggesting above is what they do. One used to go onto bed with their 4yo but he's going to bed much earlier now so they go about 9pm once the twins are in bed as they don't go to bed until later.