I don't know how you think this is a good alternative to 1 minute timers...
Not only will this put uneeded strain into the server requiring extra calculations for each joinee in the battle, but will also require extra coding for the function to be there in the first place.
What 1 minute timers give you is the ability to analyze the battlefield before anyone can commit to a battle. What would be the point of distance based tagging if, as you say, it will be up to an hour for the reinforcements to catch up to the battle (if the battle has moved from the spawn point at all)
There's just too many variables for this to be viable bro.
All you suggested can and would be addressed with 1 minute timers.