The key question is WHO you will communicate with? and the secondary question is WHERE?
Who will govern whether you would want public standard PMR frequencies or ‘private’ licensed frequencies.
If you are just communicating in your team /group then it doesn’t matter if you choose PMR or licenced. You just need a common frequency.
If you want to communicate with others then what are they using?
The beauty of PMR is that handsets can be purchased by anyone, they share common frequencies, can be bought to fit any budget and cost nothing extra to use. They are ideal for a faction at an event letting people know which frequencies are available (perhaps at a large game having a ‘control’ frequency to pass messages between the faction leader and individual teams etc)
Use of licenced frequencies gives the licence holder the right to use the given frequency. They may let others tune in on the day (if they have suitable equipment)
They are great for ‘private’ communications in a group, but are not guaranteed to be exclusive. The exclusivity is dependant on the needs in the licence application and the cost. An identical frequency can be sold to two separate groups based in different parts of the country, but if they are both airsoft teams and attend a specific event on different factions then they may conflict.
PMR can only operate on specific frequency channels and have a power limit. Licenced handsets can operate at a higher power and therefore have a longer range. However PMR range is good enough for the majority of sites.
For event running we have typically used PMR and on occasion also used site licenced frequencies. We have also used mobile phones & SMS texts/Facebook messenger etc. Only a couple of sites I’ve used had problems with range - but this affected both PMR and licenced handsets as the main issue wasn’t just distance but also the landscape. At the first when necessary we relayed A-B-C via Marshall’s across the game play, but did just as well on the phone.
The second was a mini game with an unreliable signal from the game zone to the safe zone. We had runners going back and forth anyway, so messages would be sent by them (requests for supplies, score updates etc) or would use the phone from a particular point in the game zone that had the best reception.
No matter what the circumstances - don’t be reliant on radio communications
It is technically possible to use some licencable handsets to operate on PMR frequencies (eg the common Baofengs) but this is illegal (though the chances of getting caught are slim
True PMR has the benefit of being fully legal