Victorious Heart requires you to train tier 2 or higher troops. The event lasts for 4 days and progress is reset each day at 00:00 UTC giving you a maximum of 4 collections of rewards. Whether you collect the rewards or not the progress will reset.
Training troops can't be helped by alliance help so you're relying on your speedups. You might be able to train tier 3 or higher troops but you won't be able to train 3,000 of each in a day without a lot of speedups. So it's best to train tier 2 troops for the event and convert them into higher tiers afterward. You may need to use speedups to get 10,000 tier 2 troops trained but the training speedups you get as rewards will suffice. It's also best to train all 4 unit types; Infantry, Archers, Cavalry, and Siege.