I'm afraid the Newline Designs figures are true 20mm scale and wont match with most of the plastics.
I'm already a bit concerned about mixing Italeri and some of the Strelets natives, although they should be OK, as there is always a height difference among humans.

But the biggest problem I have to face is lots and lots of conversions and usage of green stuff as not everything can be done just by painting and slight modifications with the scalpel.

Some may argue that it doesn't matter at that scale on the tabletop but for me it does.

Will have to take some more time to decide which way to go... the easy (and more expensive one) with 28mm ranges or the harder (and more friendlier to my wallet) one.

Why are the 1/72 manufacturers always making things so hard for us?

Oh well, it's a lot better then when I started with this hobby... that's for sure.