Pillager pickup entire stack of illager banner

Verification Builds:
1.16.0.63
Summary:
If two raid captain is killed,nearby pillager will pickup illager banner entire stack of it.it should pickup a single/one illager banner.pillager will pickup illager banner stack of it and becomes next raid captain.if you kill next raid captain it will drop 16 illager banner.that's weird.
Steps to Reproduce:
1.Find two raid captain and kill them.
2.nearby pillager will pickup one illager banner and it becomes next raid captain.
Observed Results:
If you throw 2-16 illager banner pillager will pickup and it becomes next raid captain.
Expected Results:
When two raid captain is killed,nearby pillager will pickup one illager banner and it becomes next raid captain.
Screenshots/Videos Attached: yes