The only problem with that system design is that there is NO EVIDENCE anywhere to show that it does what you and others claim it does. The existence of your type of system was almost exclusively founded on cardiac arrest survival and old data (early 80s) that showed improved survival w/ defib/ACLS in under 8 minutes back when only ALS was able to defibrillate.
Your system and others like it are paying millions of dollars to buy ALS equipment, maintain ALS equipment, pay for fuel, pay for con-ed, pay for liability insurance, pay for salary etc., etc. based on data that is no longer relevant. Despite this approach being around for decades now, there is no data to support it. (The cynic in me would not at all be surprised if it has been studied, but results not published due to negative results.)