Flutter will acquire Stars Group to produce an operator worth £11bn ($13.46bn) in market capital and Buhagiar can see the deal disrupting the industry for "a good few years to come."
Despite the size of the deal however, the RB Capital Co-founder believes the merger will not come as a surprise to many investors.
Buhagiar also feels estimated savings of £140m per annum will be difficult to realise.
He said: "The estimated savings of £140m per annum are aspirational at best; both companies are already trading at lower-than-expected profit margins, with significant overlap unless, of course, a large round of redundancies is on the cards, as has recently happened for some Stars employees on the Isle of Man and Malta.
"History for gaming mergers of this size has been quite eventful (read turbulent). Witness Bwin/Party, Ladbrokes/Coral and of course Flutter/FanDuel.
"Moreover, assuming local regulatory and legislative approvals take place without any delays, expect a slow transition, which will lead to uncertainties across the spectrum until the merger is finalised; it will take years to achieve the aforementioned synergies."