For someone who is buying lands from LandDAO you have every right to engage in physical verification and confirmation of your lands of you are not convinced with the use of GPS to track the location of the land. You also have the right to send a representative to confirm the lands on your behalf before involving your surveyor and legal representative to document it.
You have got nothing to fear before purchasing land from LandDAO because they have legal documents to all the lands they acquire.
All these steps might be necessary as an investor trying to be too relaxed about joining LandDAO for a profitable investment. It's normal for every investor to know where their money is going to ascertain if it's going to be profitable or not. In my little understanding about real world assets, physical assets are incorporated into digital art or tokens so the value can be sustainable.
I believe the team might have plans for all these things you have mentioned. The team must have done their own research about this project, making sure that all investors are protected from land grab from people that are indigenes of the community trying to claim properties that do not belong to them.