There is a very good article “Comparison of ESP8266 NodeMCU development boards” written by Marcel Stör that helps to understand the differences between the actual NodeMCU variants.
Yesterday I got some LoLin devices ordered from banggood.com and had to recognize that the form factor of this boards is similar to the original NodeMCU-devkit v0.9 (v1).
The following images compare the LoLin NodeMCU (v3) with an Amica NodeMCU (v2).
NodeMCU is open source hardware and software. Therefore this is no problem in general. But, if you want to include a NodeMCU-devkit into an existing baseboard you can run into problems if you do not consider such possible differences.
The Grove Base Board for NodeMCU is equipped with (female) headers that allow plugging both NodeMCU variants. Not all baseboards offer this degree of freedom.