How to initiate multiple versions of Geckodriver through System.setProperty()

I don't know if I'm overseeing something, but is it possible to use multiple geckodriver versions in the same JVM?

The problem is with

System.setProperty("webdriver.gecko.driver", "path of the geckodriver1");
driver1 = new FirefoxDriver();

System.setProperty("webdriver.gecko.driver", "path of the geckodriver2");
driver2 = new FirefoxDriver();

where I would define a system property. For a single instance this is no problem and working fine, but how can I define a FirefoxDriver with another geckodriver. Processes would run parallel so global settings would interfere with each other.

I know, that you can start multiple Firefox Session with the same driver, but I need to support different Firefox versions and am therefore looking for a solution with multiple geckodrivers as well.

Thanks in advice.