New to Holacracy. Welcome! You came to the right place to ask questions, so you're off to a great start. : )
Have completed defining roles in our organization (65), inputting all into GlassFrog. That seems like a high number for only 5 people to just be starting. Could be fine. But one thing to watch out for here (and use your own best judgment), is that there is sometimes too much psychological investment in the initial structure, which makes it less likely you'll change it. So, our general recommendation is to craft the initial structure to cover the basics, and then let the governance process start doing its thing (which is filling in any gaps). Again, could be fine in your case.
Having trouble now deciding who to assign to core roles, The good news here is that you only need to assign Lead Links. The other 3 core roles (Secretary, Facilitator, and Rep Link) are all elected. Meaning, just let anyone start as Secretary and Facilitator (usually the person with the most experience), and their first job will be to schedule a governance meeting and hold elections (respectively)!
and thinking that perhaps our organization is too small to run Holacracy? Only 5 employees, I'd say 2 people is the minimum number of people needed, so you have plenty at 5.
...so most everyone is a member in mostevery circle. Yep, that is not a problem. In fact, it's a good indication that the circle/role structure may be particularly helpful for allowing everyone to make fast, authoritative decisions without needing everyone to be involved.
Can the facilitator have other roles (and hence tensions) in a circle he's facilitating? Same with the other core roles. Yes, absolutely! That's kinda the point. What I mean is, the whole point of having roles as a distinct thing from the people, is that each person can (and likely would) have many different roles.
The big shift here is that you can't make as many assumptions about what someone does, just by knowing who they are. At any point throughout the day, a person will be shifting in and out of energizing different roles, which means you'll use some new language patterns.
For example, in a tactical meeting of the Marketing Circle with these 5 people, you would need to make some new distinctions...and of course these are just made up examples to illustrate the point...
- "Hey Bill, can I engage you in your Copy Editor role?"
- "I'd like to share some information with the group...this is coming from my Webmaster role..."
- "As Marketing Lead Link, can you take a project to find out how much money we have available to us as a circle?"
So, it's an adjustment, but not difficult. This is what it looks like in practice. You have many roles in the organization, people have a constellation of roles themselves, so the use that structure to help focus and route tensions to the appropriate decision makers.
I hope that helps!