It’s a strange thing actually, for Paul to call out the elders and deacons in the opening greeting.   In fact he does so nowhere else in his letters.

“To all the saints in Christ Jesus at Phillippi, together with the overseers and deacons”

The question is why? Why did he highlight them?

• Perhaps he was asking them to take the lead in these issues, such as helping Euodia and Syntche to agree with each other, being smart to the false teachers that were infiltrating the churches, and promoting unity in the body
• Perhaps it was because he wanted to let them know that he was Ok and the gospel was going forward, as he hoped it was elsewhere
• Perhaps it was because they were contributing to part of the bumpy issues in the church
• Perhaps it was to highlight their leadership and make sure they knew they were properly thanked for the contribution of finances and Epaphroditus

We really don’t know. It’s a mystery and one that perhaps only Paul and the elders/deacons knew about.