Windows : 6 partitions, winRe, RecoveryBoot & RecoveryImage

Question

My HDD (with windows 10) have the current partitions :

Partition 1    System             300 M   1024 K
Partition 2    Recovery           900 M    301 M
Partition 3    Primary            279 G   1329 M
Partition 4    Recovery           350 M    280 G
Partition 5    Primary            397 G    280 G
Partition 6    Recovery            20 G    678 G

I have found this forum explaining in a global way. I know that the partition 1 is for the EFI boot. The partition 3 is for the OS and partition 5 is for my files.

I am interested in are the recovery partitions. The partition 2 is for the recovery mode, and it's created by the windows installer. The partition 6 is for an OS recovery image, to reset the computer. I explored inside those 3 partitions. And I have the following structure :

Partition 2

. 
+--Boot
+--EFI
(...)
+--Recovery
|  +--WindowsRe
|     +--boot.sdi
|     +--ReAgent.xml
|     +--Winre.wim
(...)

I skipped some folders/files in partition 2.

Partition 4

.
+--Recovery
   +--WindowsRe
   |  +--boot.sdi
   |  +--ReAgent.xml
   |  +--Winre.wim
   +--Logs

and nothing else.

Partition 6

.
+--Recovery
|  +--Logs
+--RecoveryBoot
|  +--AsDiskLayout.dat
|  +--AsPartition.dat
|  +--BOOT.WIM
+--RecoveryImage
   +--install.wim

and nothing else.

---

My questions are:

1. Why I have 2 windows RE ? Is the one in partition 4 useful ? because in partition 2 the already is one, even if there is more files in.
2. install.vim is the image, but here it's said that "boot.wim file is the Windows Preinstallation Environment (WinPE)" but here is said that RE is based on PE. So do I need this too ?
3. Should I clean up and re-created all the recoveries partitions ?