ASR1001-X - What does 1 million IPv4 routes translate to in terms of transit providers

In the below document it states that an ASR1001-X can hold 1m IPv4 routes if it has 8GB of RAM. I have an ASR1001-X in production with 8GB of RAM, it's taking full table from 2 providers and a further number of routes from peering sessions.

My routing table will only store each route once, the best route is chosen so I have 1 copy of full table in there, ~700k routes across both providers and peering. I can see in BGP I'm receiving a total of about 1.8m routes.

ASR Data sheet: https://www.cisco.com/c/en/us/products/collateral/routers/asr-1000-series-aggregation-services-routers/data_sheet_c78-441072.html

My questions (more of an either-or):

1. How can I be receiving 1.8m routes when the ASR1001-X with 8GB of RAM can only support 1m routes?

2. If the above is because it only stores one copy in the routing table, why would you need 4m routes like you can get if you upgrade to 16GB of RAM?