Add frequency hopsets and the frequency management system to the list of things which makes standardizing signal systems a bit more complex than standardizing, say, aircraft towing hooks (although that was complex enough and is (was) vitally important when one considers what happens when damaged aircraft land on foreign, but allied, aerodromes).
We need to put the signaling system into its proper context – it is part of a command and control system which includes, inter alia: personnel (with the training implications), procedures, facilities (including computer systems) and communications.
Reminder: what is now TCCCS began, in the mid ‘70s as a project called ACCS 85. Col, later LGen, Jim Fox (armoured corps) was its patron. It was managed by a mixed team of combat arms and signal officers – signal officers with plenty of recent (then) and useful (then - North German plain) field experience. The acronym stood for Army Command and Control System 1985 – the thinking, then, being that ten years was enough time to design, develop and field a system which would be based on proven, mostly off-shore, hardware. The signaling systems called up in the combat development studies (Terry Liston (R22R) led the infantry study team) was, essentially, a slice of the British Ptarmigan system to serve brigade and divisional HQs (and to extend one or two ‘trunk’ links down to battalions and regiments) and a generic combat net radio system. (Despite all the bells and whistles there have, I think, been few changes in combat net radio systems since the early ‘60s – maybe even before that. Nets are still nets, ranges are still extended by RRBs, the nature is ‘one > all’ broadcasting, with complete nets being the exception, rather than the rule.)
Suffice it to say that when I retired, nearly 20 years after ACCS-85 was born, TCCCS was still not there. By the mid ‘80s we had a home made and decidedly interim trunk (switched telephone/teletype) system to serve brigade and ‘task force’ HQ. It was a systematic copy of the British Bruin system with which many Canadian senior officers were both familiar and comfortable. Computers began to creep into the field about the time I left – they had been the weakest link, I think in ACCS-85, we (combat arms and signals people, alike) simply didn’t know enough and we relied, too heavily, on our UK and US allies who were headed off in different directions. The gunners led the way with e.g. TACFIRE and BATES and we were amazed at the Brit’s embryonic WAVELL systems – but that’s all water under the bridge.
TCCCS finally got to contract for one, and only one reason: CDC agreed to build something in Calgary. NDHQ (the signals guys, especially) had all kinds of strong views re: what should be built. They even told the Minister of National Defence; I don’t know what he said to anyone. I am 99% certain that all important decisions were taken by Dan Mazankowski, the Minister of Finance and, more important, the regional minister for Alberta; I am 95% certain that Mazankowski cared little and understood less about military technical requirements – he understood that CDC had the corporate where-with-all to set up shop in Calgary, build an acceptable radio system and create jobs. Given the national aim, regional development, TCCS is wildly successful – CDC sold out to General Dynamics (I think that’s right) and they in turn sold TCCCS II to the Brits. (maybe things came full circle.)
etc. However, when you mix the two you loose alot of your bells and whistles in order to be more cohesive as a NATO force. (Unless you have a strategic link up between the two. This would be way above a COY level) 
