This is Summer from the Social Care team at Shopify. Welcome to Shopify Community!
You can certainly have two dropshipping providers in addition to your physical location, and you can even have more than two. There is no limit to the number of dropshipping apps that may be installed in your store, but it's important to keep in mind that having too many apps may affect your store speed.
Another thing to note with multiple dropshipping apps is multiple locations. When you add a dropshipping app to your store, a location will be created for the app; so when you have multiple dropshipping apps that means you have multiple fulfillment locations. If a customer makes an order containing items from different locations, shipping will be charged per location and the rates will be combined at checkout. This is important to consider as multiple locations may increase the shipping rate of an order. If the shipping rate is significantly high, it may discourage the customer from placing an order. The best way to avoid this is to offer free shipping, which is a great strategy to entice customers to place an order. If you want to learn more about combined shipping rates, you can refer to this page.
Should you have any questions about this or anything else in your store, do let me know by responding to this post!