Thanks for your reply.
A conditional discharge would only be an available option for the magistrates if they saw the offence as falling into 'Category 3', rather than into 'Category 2'. (See my first link above).
That would require them to view BOTH 'culpability' and 'harm' as 'low'. As I indicated above, I can't see them viewing 'culpability' as anything other than 'low'. It's the 'harm' factor that's 'borderline' here.
I've seen cases where fairly minor injuries (similar to those you've described) have been charged as 'actual bodily harm', so the magistrates MIGHT see 'harm' as at the upper end of the range which can fall into the 'Section 39' (common assault/assault by beating) range. If they do so the offence will be seen as Category 2, ruling out the possibility of a conditional discharge.
However 'harm' can also be taken to include psychological factors (such as when an assault on an elderly person leaves them afraid to leave their own home). Since there's no suggestion of that type of 'harm' having occurred in your case, it's possible that the magistrates MIGHT view the overall 'harm' as 'low. If they do so then it will be seen as a 'Category 3' offence. The 'starting point' sentence would then be a 'Band A' fine but your early guilty plea, together with your previous unblemished record, would almost certainly see the sentence pushed down to a conditional discharge.
So it really all comes down as to whether the magistrates view 'harm' as either 'high' or 'low'.
With regard to employment applications, unless the type of employment is exempted from the provisions of the Rehabilitation of Offenders Act 1974 [as amended], then you're not required to disclose any convictions which are 'spent'.
An offence resulting in a community order becomes 'spent' one year after the end of the order.
An offence resulting in a fine becomes 'spent' one year after the date of conviction.
A conditional discharge becomes 'spent' immediately at the end of the order.
Employment areas which are exempted from the provisions of the Rehabilitation of Offenders Act 1974 [as amended] are largely those working with children, with vulnerable adults or in the 'administration of justice', together with entry (only) into certain professions, such as accountancy. See the Annex to this document:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/409805/DBS_guide_eligibility_v7.pdf