I say no issues. I have mixed 1/32 aircraft and civilian vehicles with 1/35 figures and armored vehicles on many occasions. The difference is not great enough to see as long as they are not two like items (two jeeps for example)one in 1/32 and one in 1/35).
You can also mix 1/32 and 1/35 figures, since people come in all sizes as well.
The key to mixing the figures and different scaled vehicles is to keep constantly-sized common items in one scale. For example, keep all weapons in 1/35, or all helmets, all canteens, all grenades, etc.
Some examples:

