For Vasart Ltd, canes are very often set "high" out of the ground, rather than being marvered smoothly into the surface. And very often some of the canes tend to lean one way or another. Also, the setting of the pattern is often not of the best geometric precision. Another feature is that overall the canes can seem to be "spaced apart".
For Strathearn, there appears to be much more control over the spacing of canes and the neatness of the pattern. Although many Strathearn weights have canes set "high" out of the ground, the height is usually not so much as for Vasart Ltd. Some Strathearn weights do have "falling over" canes but this is less often seen and may only have occurred in the first few years of the transition from Vasart Ltd. to Strathearn.
But there are no hard and fast rules. As ever, it comes down to the overall look together with individual details. There are some very neat and very well set Vasart Ltd weights and some Strathearn pieces do look a bit untidy.