Are you trying to change the boot order of the guest OS inside the VMs? Or are you trying to determine in which order the VMs are started by the host service? i.e. is this what you are looking for?
PS C:\> gcm -CommandType cmdlet *startpolicy*
CommandType Name Definition
----------- ---- ----------
Cmdlet Get-VMHostStartPolicy Get-VMHostStartPolicy [[-...
Cmdlet Get-VMStartPolicy Get-VMStartPolicy [[-VM] ...
Cmdlet Set-VMHostStartPolicy Set-VMHostStartPolicy [-V...
Cmdlet Set-VMStartPolicy Set-VMStartPolicy [-Start...
[vExpert|http://www.vmware.com/communities/vexpert/], PowerShell MVP, VI Toolkit forum moderator
Author of the book: Managing VMware Infrastructure with PowerShell
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