Why the value of 1 Shilling 6 pence (18 pence) and 3 Shillings was chosen for silver token issues either private or Bank of England issues

[rpeddie 119]

I have searched through a few references for this and cannot find mention or explanation.

Basically just looking to see if there is any information on why these denominations were chosen, and what were they trying to achieve by straying from the norm?

A few of the suggestions i already have found through past questions, is these values were chosen simply to differentiate between the official issuance and to mark them out more clearly as a token issue, but I would like to hear if there are any other reasons for going down the route of different denominations.

 

[Peckris 2 2,127]

I assume that as they were planning the Great Recoinage of 1816 they needed to be sure there was no denomination overlap to cause confusion?

[shagreen 24]

From memory, their silver bullion value was less than the denomination so they had to be classed as token

[Sword 1,471]

There are private silver 1 shilling tokens but they do not bear a portrait of the king. The BoE tokens all have portraits on the obverse. It is certainly plausible that they had different denominations to prevent any confusion with official coins.