They are 54 mm. It is not known if these have bases. Friend lost these when he moved to the new house. I am trying to help him to restore his grey army.
My money would be on New Hope Design. They employed at least 6 Sculptors and used to release figures as they appeared in the Osprey Books. I would suggest you look for an early title from them on Romans, and you should find them amongst the Coloured prints. Ray
Looks possible, As I said, they had a number of different Sculptors and they used to advertise which Sculptor did which figure, so it was hard to identify their styles, until they had done a number of figures. The 2 figures you displayed are obviously 2 different styles so 2 different sculptors. Take a close look at their faces and see the difference. Ray
A web search on "new hope designs miniatues" turned up Battleguard Ready, https://battleguardready.com/ They apparently own New Hope Designs now. You could try contacting them to confirm whether those figures are New Hope or not.
New Hope Design
I tried some years ago to reconstruct from different sources, alis of their production with pictures when availables
You can download an Excell file from here https://www.mirofsoft.com/nostalgia-old-catalog-pdf/