@greg67
I don‘t quite understand. I only do these three supersets on upper body days, no isolation or other exercises. So I can‘t reduce time anywhere else
I said one way to do it. You're doing 18 total sets, 6 per each superset.
At the VERY least you should be doing
pairing which is dips, 1.5 mins, rows, 1.5 mins, etc. This makes it so you have some rest between each set so you can recover better than doing bother exercises in a row.
If you don't superset the pullups, then pullups, 3 mins, pullup, 3 mins, pullups 3 mins takes about 10 minutes. Then say pushups, 3 mins, 3x takes 20 minutes. Then you superset the last two it should take about 10 mins per superset which is another 20 mins total.
This should take 40 mins max.
Even a full body routine should take around 1-1.5 hrs with proper pairing. I have no clue how you're assuming it's going to take 3 hours.
But ok, look, you're the one who wants to improve on pullups. I've told you why the quality of your sets are bad. It's up to you to make changes. If you're just going to give more excuses why you can't rest more then you're clearly not tired of not getting better at pullups.