Is it safe to install two versions of ionic cli (latest and 3.4)?

I am currently using the latest version of ionic CLI. Recently started working with a starter app which has some conflict with latest ionic-cli (3.6.1) and the developer suggest to use ionic-cli 3.4. Is it safe to have two versions of Ionic cli or they will conflict and I must install latest before installing 3.4?
Latest was installed globally (npm install ionic -g)

If you don’t get any better answers, it is possible to install completely different node/npm environments using nvm or nvm-windows and switch amongst them easily. That would eliminate any conflict with globally installed ionic-cli versions.