World of Tanks copes quite well with low powered machines. They have a huge user base in areas where hardware costs a relatively high. So they need to make sure their game runs smooth and looks great even on low powered and inexpensive hardware. Which it does. You'll be fine. WOT is far more sensitive to network latency than hardware horsepower, in my experience.
Google/Youtube some videos on the subject and see for yourself.
If you have the hardware already, then download the game and play it. It's free to play. You have nothing to loose.