All of them has their own groups vs All of them have their own groups

Some examples from the web:

• This is also replicated in my own group.
• Oxytocin can bias people to favor their own group at the expense of other groups.
• Whatever the answers to these questions, I should like to thank all of my colleagues, particularly those from my own group, who intend to vote in favour of this resolution today.
• There is a common resolution which has been put forward by several groups, of which my own group, the Greens/European Free Alliance is one.
• Of course, I expect that Members of the groups will discuss these matters within their own groups and reach a final decision on it.
• As in all groups in this House - no, sorry, except perhaps for the Greens - there are differences of opinion within my own group.
• I understand that the groups did not share our view - neither my own group nor the Socialist Group.
• Then we'll make our own group.
• I said, You make your own groups of four.
• That is why I cannot support my own Group's Amendment 1.
• You should start your own group, Jennifer.
• Has her own group in Kastrup.
• My own group has studied with great interest the work of the European Monetary Institute.
• Many in my own group have raised this question with me.
• He formed his own group - Propaganda of the Deed.
• He formed his own group - Propaganda of the Deed.
• Wyatt was eventually sacked from his own group.
• Has one's own group in Kastrup.
• Own groups are only 9 meters thick.
• What we do is start our own group.

Some examples from the web:

• This is also replicated in my own group.
• Oxytocin can bias people to favor their own group at the expense of other groups.
• Whatever the answers to these questions, I should like to thank all of my colleagues, particularly those from my own group, who intend to vote in favour of this resolution today.
• There is a common resolution which has been put forward by several groups, of which my own group, the Greens/European Free Alliance is one.
• Of course, I expect that Members of the groups will discuss these matters within their own groups and reach a final decision on it.
• As in all groups in this House - no, sorry, except perhaps for the Greens - there are differences of opinion within my own group.
• I understand that the groups did not share our view - neither my own group nor the Socialist Group.
• Then we'll make our own group.
• I said, You make your own groups of four.
• That is why I cannot support my own Group's Amendment 1.
• You should start your own group, Jennifer.
• Has her own group in Kastrup.
• My own group has studied with great interest the work of the European Monetary Institute.
• Many in my own group have raised this question with me.
• He formed his own group - Propaganda of the Deed.
• He formed his own group - Propaganda of the Deed.
• Wyatt was eventually sacked from his own group.
• Has one's own group in Kastrup.
• Own groups are only 9 meters thick.
• What we do is start our own group.