Capn Rex Havoc
To address your point.
The instruction has to be issued at some point in time to make it clear that you have a required time to arrive at the feeder fix. So what should the phraseology be if you don't like the current way? "ABC123 can you cross ARBEY at time 46? .... ABC123 negative best time is 43....ABC123 roger expect vectors, cross ARBEY 46 at 250kts .... ABC123 ARBEY 46 250kts " or "ABC123 can you cross ARBEY at 46? ... ABC123 affirm ... ABC123 cross ARBEY at 46 at 250kts....ABC123 ARBEY 46 250kts"
How is this better than "ABC123 cross ARBEY at 46 at 250kts .... ABC123 ARBEY 46 250kts (we'll need vectors/holding)"
So you don't like being issued with unrealistic reductions. You are in essence asking us to make a judgement call as to who we think might be able to meet the time without holding or vectors. Easy for this example of a heavy for 10mins at 200nm, I am sure you won't make it. But what if was 7mins at 250nm or 4 mins at 210nm, we simply don't have the time to make a judgement about it being unreasonable or not. When we first started issuing feeder fix times I was amazed at how slow some aircraft can go especially after the pilots got the hang of it and would often issue times which I thought they would have no hope of making without vectors but they did. It is just much easier to issue the time then you tell us what you need. Don't take it personally or think that we have no understanding.