I am one of those that feel that the Bolt Action (metal) and Perry Miniatures figures are too different to use together.
Of course, YMMV.
However BA do not do North African theatre figures, so I just use Perry figures for them. Currently I have only Perry vehicles, though your Panzer III is probably going to be a DAK one and at Warfare I hope to get two Crusaders, one of which will end up as a tank.
I would almost want Perry compatible figures for North Africa and BA compatible for 1944+ Europe, though that would be commercially non-viable.
The Tamiya 38mm figures are not a good comparison for size.
I am not sure if am comparing them correctly, but the 100% figures look nearly a head taller than both BA and Perry. I know when this was being discussed elsewhere [url][http://ultravanillasmurf.blogspot.co.uk/2014/04/perry-miniatures-eighth-army-comparison.html[url] that I had difficulty finding a figure from either with a neutral standing pose.
Any chance of a picture of the various size figures against a rule?