Shop 'n Save's Muir Glen Catalina Deal

I love Catalina coupon offers at Shop 'n Save, especially when you can shop for free.

You will need access to several computers to print the internet coupons. Shop on Thursday, 4/23 to get the extra 20% off before coupons with the $10 off $50 purchase. And keep your total purchase to just over $50.

Purchase 5 Muir Glen products and get a $3 coupon to use on your next purchase.

Participating products:
Muir Glen Organic Tomatoes or Sauce, 14.5-15 oz. 2/$4
Muir Glen Organic Pealed Tomatoes, 28 oz. - 2/$5
Muir Glen Organic Tomato Paste, 6 oz. - 4/$5
Muir Glen Soup, 19 oz. - 2/$5

Coupons available:
$1 off any Muir Glen internet printable
$1 off any Muir Glen internet printable (register with the Connoisseur's Club)

:: Deal Scenarios ::

Buy 5 (14.5-15 oz.) tomatoes or sauces $10 (5 x $2)
Thursday 20% off -$2
Use 5 $1 coupons -$5
Receive $3 Catalina coupon
Net price: Free

Now, if Shop 'n Save didn't have the policy where internet coupons are accepted for only up to 50% of the retail price:

Buy 5 tomato paste $6.25 (5 x $1.25)
Thursday 20% off -$1.25
Use 5 $1 coupons -$5
Receive $3 Catalina coupon
Net price: $3 money-maker

My opinion: I don't understand Shop 'n Save's internet coupon policy. In both scenarios, I would be using the exact same coupons and they come from the manufacturer's web page. Why do they have this policy?