In a standard system, 1 and 3 second are for Duration A and B respectively, making one two-tone page 4 seconds long?
Yes, but in practice all sorts of variations are found. The county system here has a large collection of agencies on channel, some using very old equipment. Most are Plectron but there are some Motorola and a few that use non-standard tones. Evidently they determined that to make everything work the timing needs to be 2 seconds for tone A and 3 seconds for tone B. That's the way every tone out is transmitted on the system. Fortunately all this timing stuff will be of no concern once the new firmware is released.