Barrows & Rarrows

Hi fellow managers! What are the latest findings regarding arrows? Going through threads I find that some managers like to have rarrows on the strikers and barrows on defenders, others think it is useless.

Do we really know what they do?

Personally, I dont think they change player position when attacking or defending. I believe they change the mentality of the players. That is why I like to put barrows on all of my defenders when I have attacking mentality.

This is just one of many theories though, I have no proof whatsoever of this. Just a feeling that my defenders rating are slightly higher with barrows.

I believe it's linked to mentality but i tested blue arrows on CB's and my CB scored from a cross from my CM in play so god knows what's going on there. My CB never scores or shoots in play.

I think that arrows are useful to strengthen team in attacking or defending part of game. I use arrows according to mine and opponent's formation based on "balanced" philosophy. This means that i'm trying to balance my teams strength in both att and def part of game.
For example I use more red arrows when I have 1ST in order to support him in attack by other players and I use more blue arrows when playing with 3ST to help team in defence.
How it looks combined? I will give 2 rough examples, fine tactic adjusment depends on opponent which I won't include now, so won't use mentality and pressing settings:

43n3: mixed/long passing through middle, zonal marking, normal/hard tackling, optional counter attack
---ST-ST-ST
---MC-MC-MC
-DL-DC-DC-DR

4141: mixed/long passing, zonal marking, normal/hard tackling
------ST-----
-ML-MC-MC-MR
-----DMC---
-DL-DC-DC-DR