To elaborate further, the turtle strategy basically is the opposing alliance telling you “We’re confident that you can’t score enough rings to make up this difference.” So, prove them wrong.
Let’s take a look at my handy-dandy scoring calculator. Assume the Autonomous Bonus is a tie in all these situations.
The situation you described (Situation 1), assumes that the blue alliance takes control of 4 mobile goals, then parks all goals and robots on the platform for the rest of the match. To beat it, you just need to take the 3 remaining mobile goals, score 14 rings on their branches, and balance everything on your own platform. Voila! You win by 2 points.
Situations 2 is similar, but includes the blue alliance scoring a few rings of their own before balancing everything on the platform. The same strategy still applies, and can still be overcome, you just have to score a few more rings.
Situations 3 gives the Blue Alliance even more rings. This can still be overcome, but you’re likely going to need to utilize the high branch, if it’s still available to you.
Situation 4 goes so far as to give the blue alliance 5 mobile goals instead of 4. Spoiler alert, this deficit can still be overcome!
If an alliance wins a match by realizing their opponents can’t overcome this early deficit, kudos to them. But personally, If I lost a match to two robots that were sitting idle in a corner for 75% of the match, I’d probably re-evaluate my own robot / strategy.