I personally never experienced the scenario to roll up historical data. But the Adobe Link Rollup and Global Report Suites says that Rollups can aggregate historical data, while global report suites only report data from the point they were implemented.
Global Report Suite by multi-suite tagging is based on direct server call with prices (even though it is secondary calls) so its features are pretty same as a single report suite. Like a report suite cannot get data before the tag or creation started, global report suite cannot get data from other report suite.
Furthermore, roll-up report suite is free but it also don't take historical data.
Global Report here indicates Roll Up Suite or Global Suite?
If it is Global Suite, the data will be available only from the date of implementation & not the history. You can check with your Account Manager to sum up individual Report Suite numbers, but it will incur cost.
If it is Roll Up Suite, it can aggregate the Historical Data.