One way that T-Mobile USA and Sprint could reduce their 5G capex bills, and placate investors and international parent companies, would be to combine their efforts, in a joint venture or a full merger. The two companies have danced around one another before, and now merger talks are reported to be back on, no doubt encouraged by a new government which is expected to be more laissez-faire when it comes to approving major M&A deals. Sprint’s parent, Softbank, previously came close to bidding for TMO in 2014, but backed away in the face of probable opposition from the antitrust agencies. Earlier this year, with a new administration in place, Softbank chairman Masayoshi Son hinted that he would be interested in…