Wild Arugula taproot damage when transplanting

[jiemslie]

How bad is it when the taproot of a seedling (few days old) wild arugula gets damaged when transplanting? The worst damage was probably half of the ~7cm long taproot got snapped off.
I read that this means plant could die or get permanently stunted yet i've also read that this could mean more roots could branch out from that broken taproot which is apparently a good thing. Anyone have any definitive proof which is true? Perhaps from a study/research paper or project. Also what if this happens to kale (do they even have a taproot)?

 

[Meadowlark]

Also what if this happens to kale (do they even have a taproot)?

I don't grow arugula myself...don't care for it. However, just yesterday I pulled out my winter Kale.

As you can see the root system of this plant which was over three feet tall when pulled is pretty extensive...but without a defining a tap root that I can see.

In general, it is not a good thing to mess with root systems of veggies. I have never seen that to be a positive thing.