Red Hare the rider has the issue of being from the lost belts. Its not a usually summon able servant in its form just like Ivan would need a rework to be a standard servant berserker, or rider not withstanding. In this case you saying you'd be summoning the ship. That wouldn't be how summoning works in specific in normal human history like chapter 1 of FGO. It'd be like if the Queen Anne's revenge somehow was summoned instead of blackbeard.