They are already operating here with a 14% market share in the postpaid market, so if they are not currently a security risk, then it is difficult to argue that they will become a national security risk after hitting a 38% market share under a merged entity. If regulators have a problem with the new combined market share, then it will also indirectly close off any M&A between the big 3, and the market will continue for a long time with 4 players.
The main reason why they have the capability is because of their market valuation and possibly a better financial market as their backing. They are listed on ASX, and with only a 14% SG market share, they are already being valued at AUD2.5b before the acquisition announcement. All they need is just to sell another AUD400mil new equity to complete the purchase, with the remaining probably financed through debt. It took them a day to complete the 400mil placement without any discount, and these new investors magically earn 30% the next day.
https://www.marketindex.com.au/asx/tua?src=search-all
https://data-api.marketindex.com.au.../inline/completion-of-institutional-placement
In terms of profitability, they have been making losses for the past few years and only managed to turn a profit recently with 3m net profit for their latest half year. In comparison, SH trading on SGX fetched a market cap of SGD2bil despite having a bigger market share and higher net profit.
https://data-api.marketindex.com.au...pdf/inline/appendix-4d-half-year-results-fy25