Overlappping Related Employer Groups

[Gilmore]

Dr A's PC is a partner with two other Dr PCs in a medical practice. The medical practice sponsors a plan benefiting all four members of the ASG (the three PCs and the medical practice).

Dr A's spouse, DR S is also a Dr in an unrelated field and has his own PC, with no employees. Drs A and S live in a common-law-state, and have minor children.

So it appears that Dr A's PC creates an overlap between the ASG and the CG.

If Dr S becomes an employee of Dr A's PC, Dr S will become eligible for the plan of the ASG.

If Dr S adopts a plan for his PC, and assuming Dr A's PC does not adopt Dr S's plan, does Dr S's plan affect the plan of the ASG?

I know that Dr S's plan must consider the employees of the controlled group (meaning Dr A's employees), but does the overlap extend to the ASG employees?

I've received one opinion that, because Dr S is an employee and HCE of the ASG (by being an employee of Dr A's PC), then his separate plan under his PC cannot benefit him without taking into consideration the other employees of the ASG.

I've also read, however, that there does not appear to be any requirement for the members of the controlled group to consider the members of the ASG even if there is an overlapping member. I could see an issue if Dr A's PC adopted Dr S's plan, but not so clear if Dr S's plan is NOT adopted by Dr A's PC.

I appreciate any thoughts.