Airfix Ancient Britons - rediscovered

These are the rediscovered these Ancient Britons. This army was painted by my friend Stuart Asquith and I bought it from him back in the late 1970s for the princely sum of £5.  They were handed over in a pub just around the corner from the old Minifigs Shop in Gillingham Street, London Victoria .

My problem is that these are based for the old 5th edition WRG rules.  Light Infantry and skirmishers are on single figure 30mm square bases, Medium Infantry are 3 figures on 20mm x 30mm  bases and heavy infantry on multiples of 15mm by 20mm. The Ancient Britons warbands are all classed as medium infantry.   As you can see from the pictures, the skirmishers take up a lot of room.  The question is should I rebase them and the Romans?

The cavalry are all conversions of the US cavalry figures with cloaks of plasticine and home made shields.