Special:IPContributions lets you view contributions over a CIDR range. There is no "smart" (i.e. not spamming the TAIV logs) way to get all TAs on a CIDR range. A endpoint to get all contributions from all TAs on a CIDR range would also be nice.
Of course, the largest CIDR range would be /16, like Special:IPContributions, to prevent fishing.