Going. By your logic ,if one terminating station captures ( utilises )good condition & brand new loco other 2 zones ,but sent it's own loco With out coming trains ,will not it affect it's TT .If same category. Loco. ,no issue.
But if instead.
E.g wap 7 is incoming loco but return sector it is given wap 4 or wap 2 won't it have problem
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have seen. In IRI ,the Zone or station which will provide loco link is mentioned along with trains service on Resumption or for new trains .
Pl correct me if I am wrong

It is a valid concern, but barring some trains with very, very aggressive schedules, for the most part, WAP4/5/7 doesn't make a big difference for the train.

The trip shed staff are already aware of the loco requirements for all the trains they have to provide links to. So, when the regular link for a train is unavailable (the loco may need additional time for minor maintenance at the trip shed due to issues, it may have been used as a replacement for another locomotive on another train etc), they'll see...
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which loco within their current holding in the trip shed is suitable for the job and allot it.

If it weren't for the HOG requirements, given how the schedules for most trains are, WAP4/5/7 would be able to handle the job equally well on most routes. So, these offlinks are not a problem.

For the loco allotment, the zone doesn't matter. Only things that matter are
1) Is the loco sufficient for the train
2) Does the loco satisfy all the basic maintenance requirements (no outstanding issues that need to be fixed at the shed, enough time left in it's regular maintenance schedule etc).