iOS simulator with Grid : wrong one is launched

I’ve 3 different machines. On each of them, I’ve connected a different iOS Simulator on Grid.
On one I’ve got an iPhone 7 iOS 11.1
On the second I’ve got iPhone 6 iOS 10.3
And on the last one I’ve got iPhone 8 iOS 11.3

I launch a test on iPhone 6 iOS 10.3 with Webdriver I/O and Appium, with these Capabilities :

browserName: 'safari',
platformName: 'iOS',
platformVersion: '10.3',
deviceName: 'iPhone 6',
shutdownOtherSimulators: true

But I can see that a simulator iPhone 6 iOS 10.3 is launched on my 3 machines. I was expected that only one machine was running the test.
So is it normal ? Why appium don’t see that iPhone 6 is only available on the 2nd machines ?
Thanks a lot

As example, this is confusing of the first machine with the iPhone 7 iOS 11.1 connected :

browserTimeout: 0
debug: false
help: false
jettyMaxThreads: 0
port: 4723
role: node
timeout: 60
enablePassThrough: true
cleanUpCycle: 2000
maxSession: 1
capabilities: Capabilities [{shutdownOtherSimulator=true, browserName=safari, maxInstances=1, version=11.1, deviceName=iPhone 7, platform=IOS}]
downPollingLimit: 2
hub: http://localhost:4444
id: http://XXX.XXX.XXX.XXX:4723
hubHost: host.url
hubPort: 4444
nodePolling: 5000
nodeStatusCheckTimeout: 5000
proxy: proxyUrl
register: true
registerCycle: 5000
remoteHost: http://XXX.XXX.XXX.XXX:4723
unregisterIfStillDownAfter: 60000

And when I check y grid, I can see my 3 machines with, for each, the expected version of iOS connected :