does anyone know if this is possible?
It sounds like you want not to meet the other ordos, which accompany these fleets often. Give your Freighters and Tankers millitarized subsystems (makes them way less visible) and improved sensors and switch off the transponder in the system. Consider also to go dark, when neccessary. Then you should have way less problems to get (only) the fleet you want.
I disagree, it is unwise to add militarized subsystems in an end-game fleet - simply because then your skills such as flux bonus and damage bonus would get diluted on such ships. militarized subsystems is only useful when your fleet is small and you still have room for adding militarized subsystems without wasting your skill bonuses.
If you encounter the problem of 5 ordos chasing you - simply hide in a nebula and/or ring system, go dark, and then usually the ordos split up searching for you. What they do is usually remain their course when they have chased you - so basically you have to sorta move sideways from their trajectory once you go dark. Once your target fleet is somewhat separated - go after it, and after the battle immediately go dark and hide incide the debree created by fight - there is a good change the other ordos will lose you again.
Also, it is important to have good fleet speed - which is why I have 4 ox tugs in my fleet, so I have 20 sustained burn speed.
*here input a scene with saruman and grima from lotr:
"- But my lord, youll need a number of supplies and fuel - thousands - to sustain 4 ox tugs!
- Tens of thousands!
- But my lord, there is no such amount!"
*trumpet sounds, followed by screenshot*
https://drive.google.com/file/d/16SAZxwXT7o6qBdLbMDPWFVcQm2WO37w4/view