A sequel of topic #23273. This may be controversial topic, feel free to disagree with me into oblivion. But I learned that the point of tags is for searchability.
We know there are three Girls' Frontline characters that represent each caliber-specific variants, UMP40, UMP45 and UMP9. H&K UMP is still a correct umbrella term. However, in context of illustrations, those differences remained significant. All the guns bear no visually-distinct features in general, other than UMP9's curved magazine profile, while UMP40 and UMP45 ones are straight. Even according to the Wikipedia page, UMP's barrel length are the same (200 mm) regardless of variants.
For the similar reason we have H&K MP5 without adding redundantly specific H&K MP5/10 or H&K MP5/40. Note that early 9mm MP5 models use straight mags just like its 10mm and .40 S&W counterparts.
This issue is different from a poorly-thought aliasing request for M16, M16A2, M4 Carbine, XM117 and so on into single AR-15 tag. Or even worse, aliasing AKM, AK-47 and AK-74 into a single Kalashnikov rifle tag.
There are noticeable distinct features between each rifles based on the same platform.
I wanted to maintain weapon names and classification technically-correct while not causing tag clutter.
Almost treated them like character names. Thank you for reading this suggestion. I welcome second thoughts.