why I have the same divide on my 2 different account?

• The name of the device you see is determined at Settings > About > Name. When restoring from a device/backup the previous name is transferred as well. Multiple devices can have the same name.
• A single device can use 2 different Apple Account. One is the main account at Settings > [name on top], and the other is used for Media and Purchases at Settings > [name on top] > Media & Purchases.

I believe it takes the name from whatever you give it in the Name part of Settings.

To change the name of your iPhone, iPad, or iPod touch, follow these steps:

On your device, go to:

1. Settings > General > About > Name

2. Tap the Clear Text button (X), enter a new name, then tap Done

From:

Change the name of your iPhone --> Change the name of your iPhone - Apple Support

Change the name of your iPad --> Change the name of your iPad - Apple Support