The initial error is (y - y_hat)^2 where y_hat is mean(y1, ... yn). So the error is divided up among the y1...yn sequence based on how bad they contribute to the y. If models are trained separately, then thefull error of y is backproped. If the models are trained together, one model might have a lot of error which will influence the proportion assigned to the rest which I believe effectively lowers the learning rate. Is this what you mean by "loss values will be smoother."
twocupv60 OP t1_iytf8ei wrote
Reply to comment by Zealousideal_Low1287 in [D] Ensemble Training Logistics and Mathematical Equivalences by twocupv60
Thank you. Figure 1 is exactly the models I am considering for this problem.