Tremor Rod and Skitterbots and mine re-arming

Hi all, so both tremor rod and skitter bots can re-arm mines, after a 5 second delay.

You also have a limit, lets say 20 mines with some investment.

If I throw 5 mines per skill use, how does the re-arming work? If I only throw 20 mines total, do they each go off three times (once due to skill, one extra for tremor rod, one extra for skitterbots)?

If I keep throwing continuously, am I overwriting the old mines, so they only go off once?