Tyres are tyres. Most of the racing tyres which have been available for classic racing bikes since the 70s have been road tyres. Some have had better compounds. But if your bike remains more upright in corners due to it's steering geometry, the compound is less relevant. The Japanese two strokes of the 70s had 18 inch wheels and neutral steering. They leaned much more than a Manx so needed better tyres. But when a wheel of a motorcycle is touching the road there are three directions of load - vertical, sideways and rotational. If there is more sideways load, when you apply more rotational load, you need more grip. If the bike stays more upright in corners, you do not need as much grip to do a similar speed, so you can accelerate faster with the same compound tyre.
In corners the Japanese bikes were no faster than a Manx. But once out of the corners, and onto the straights, they were faster.