Firstly, you should note that Fido generally does not price match phones or plans and services. However, there have been occasions where they have offered special promotional plans in response to promotional plans offered by other providers.
That said, are you sure Rogers is offering the device at a better cost? Many of Rogers' advertised offers are based on their Upfront Edge financing.
That model is a akin to a lease model. Yes, the upfront costs and monthly fees are less costly, however, you don't actually own the phone at the end of the contract. Once the contract has ended, you would be required to return the phone (assuming its in adequate condition) or pay out the balance of the device. Fido does not offer a lease model for obtaining devices.
On the other hand Fido offers their devices using a financed model. At the end of the contract, you do own the phone. It's true that Rogers does also offer a financed option which does not require an upfront cost. However, their monthly fees in that situation are usually more than that of Fido's option with upfront costs. Both financed options tend to result in similar total costs for the phone.
The different providers offer different options for providing customers new high-cost devices. When comparing the different offers, it's important to make sure you're comparing similar offers. It's very unlikely that any mobile provider will offer a particular device at a significantly different cost than the other providers. It would be personal preference as to which option (ie financed, tab, lease, etc) suits them best.
Hope this helps 😀