I guess:
the first crawler use Selenium framework, right? The program will open browser window (as you mentioned, use Chrome Driver), the program then wait the browser window render the web pages complete, after that it scrape data
the second crawler use HTTP request directly, so it will be quick, but HTTP request can only get the original source of the pages, it cannot run javascript to render the page.
It's impossible to combine the 2 aspects directly, but there is another way to speed up. That is use multi-threads, to use multi-threads, the tasks must could be split into sub tasks, such as you have 10000 pages to scrape, you can put into 10 threads, each thread 1000 pages.