Personally, I’ve never encountered little people being used that way in English, but I’m not a native speaker and since there are some similar phrases in German I’ve no doubt it can refer to unknown or invisible helpers instead of midgets, children or dwarves/hobbits.
There is a fixed expression, der kleine Mann auf der Straße ‘the little man on the street’, which refers to Joe Sixpack (aka. Otto Normalverbraucher) and has no common female counterpart, but a related plural form, die kleinen Leute ‘the small/little people’.
Maybe one of the following suggestions fits better:
- Menschen hinter den Kulissen or … dem Vorhang, … der Bühne ‘people behind the curtains’
- Leute im Hintergrund ‘people in the background’
- viele fleißige Hände ‘many busy hands’ or, with alliteration, helfende Hände ‘helping hands’
- Helfer ohne Namen / namenlose Helfer ‘nameless helpers’
- unbekannte Gesichter ‘unknown faces’
- hilfreiche Geister ‘helpful spirits/ghosts’
- gute Seele ‘good soul/spirit’ – usual a single low-level but beloved employee, a mother or father figure
- unzählige Beteiligte ‘countless parties involved’
- wahre Helden ‘real heroes’
- (Zahn-)Räder die die Maschine(rie) am Laufen halten ‘(gear) wheels that keep the machine running’
- alle, die einen/ihren Beitrag geleistet haben ‘everyone who contributed’
The following can be rather accusing or derogatory:
- Mitläufer ‘tag-along, hanger-on’
- Kollaborateure ‘collaborator’
- Helfer und Helfershelfer ‘helpers and their helpers’
Fußvolk
means the base [ant] members of an organisation/institution in contrast to the top members/élite.