Social media, at times, could get tricky to understand. That's where you need an expert advisor to help you leverage social media, making most out of time and capital investment. Even tagged as social, no two social media platforms are same and likewise varies their usage for specific business objective. Having multiple presence on same social platform isn't something new. But, those are for some massive companies.

The question you should ask yourself is:

1. What are you trying to simplify by multiple presence?
2. Can there be simple, not simpler, process to achieve the objective?
3. What are the specific purpose behind choosing specific social platform?
4. Is it all about customer service or something more?
5. Is there an alternate audience that you're trying to reach which your primary account can't achieve?
6. Where would the distinction lie between your primary account activity and sub-accounts?
7. How will you manage and brand different accounts?

Hope above helps!!

Certainly using the hashtags on a single account is the best recourse for efficiency; however, as you are finding it does create some confusion and does not seem as personalized.

If you are not wanting to set up a separate Twitter for each city, you could set up a Twitter account for event changes and a separate account for event messages. (e.g. follow our Twitter channel for important notices about your upcoming event).

Facebook allows you to display pages by location. You could use this. To manage events, use the events Facebook widget. As to managing several accounts, there aren't any rules per se but there is one clear thing you have to remember: if you have too few and unreliable resources, the more accounts you manage, the more risks you run. Try and keep one account per country and manage it properly. What I have seen happening over the years is companies - like airlines - creating umpteen accounts, then failing and consolidating their accounts. Once they learn how to use them properly then they start ramping up, as their social media budget picks up. Don't think that social media is free. It is people intensive.

In my opinion too many accounts can be evil, but it is not necessary, you can have one account and can do your job with it if you manage it well by relying on local to connect with communities. Remember that by balancing the competencies of your corporate office and your local franchises, you will make more authentic connections with more engaged local audiences.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath