Using the same game engine for copy and paste job is no way to show that a game is "new and improved". For example: WWF War Zone/Attitude were the first two games Acclaim created using this engine. These went on to be part of PS1's Greatest Hits.
As for ECW, not so much. After the relationship between WWE and Acclaim ended, Acclaim still wanted to be part of the wrestling gaming business. EA had an agreement with WCW. WWE had an agreement with THQ, now with 2K due to bankruptcy. Acclaim turned to ECW to publish their first game.
Same graphics, same concept, plot, and voice overs before the match starts--not to mention the difficult controls. There were new matches introduced in the game, but that didn't spark interests among gamers unless you are ECW fan. This wouldn't be the last time Acclaim published a wrestling game. Which brings me to the last game on the list.