Which data problem do you have?
Wunderkind and Bluecore both talk about identity, but the emphasis is different.
Wunderkind is about identifying visitors and triggering messages. Bluecore is about using shopper and product data to personalize retail marketing.
Where Wunderkind wins
Wunderkind wins when the opportunity is anonymous visitor recovery. If identifying more people creates more reachable demand, it is closer to the problem.
Where Bluecore wins
Bluecore wins when the opportunity is product-led personalization. If catalog behavior and shopper history should drive campaigns, Bluecore is closer.
Where Sequenzy fits
Sequenzy fits when the data problem is not that advanced. If you need to email known customers better, keep the tool simpler.