Do you need a solution like this?

3 different delivery zones with different charge bands and rates dependent on either wt or value and 2 different methods.

Method name	Country	Wt or Value	Charge
Normal 1	CA	0 - 20	5.00
		20 - 25	1.00
		25+	Free
Method name	Country	Wt or Value	Charge
Normal 2	US	0 - 30	15.00
		30 - 50	10.00
		50+	Not Available
Method name	Country	Wt or Value	Charge
Normal 3	Rest of the World	0 - 20	5.00
		20 - 25	1.50
		25+	Free

Method name	Country	Wt or Value	Charge
Express 1	CA	0 - 20	15.00
		20 - 25	5.00
		25+	Free
Method name	Country	Wt or Value	Charge
Express 2	US	0 - 30	25.00
		30 - 50	15.00
		50+	Not Available
Method name	Country	Wt or Value	Charge
Express 3	Rest of the World	0 - 20	5.00
		20 - 25	1.00
		25+	Free

So the bands and rates can change for each delivery destination as can the names.