Tall against short

Hi,

I am a big fellow, 6'2", 280lb and my build has been developed partly as a result of cattle farming so lots of upper body strength and a certain immunity to being kicked and thumped!! I have in the past done a lot of judo, ninjutsu and shotokan karate but managed to completely wreck my left knee with farming and karate and gave it up. I am loving the groundwork and the locks (amazing how it all comes flooding back) but I am having major hassle with throws like ippon/morote sieonage, ogoshi etc. - basically, anything where I have to get an opponent on my back or hip and lift using my knees. I remember always being rubbish at these throws as my right achilles tendon is about an inch short so motion is seriously limited in that leg which has also contributed to my knee hassle.

I have tended towards throws like taniotoshi and taiotoshi and the winding throws where I can use my weight to gain lots of momentum.

Any ideas on adaptations that can be used for the lift type throws? I was thinking of trying these throws whilst dropping to one knee. Is this any good for tall against short as I am having some bother against the shorter and really powerful guys (our club is on a military base!)?

Thanks

Kneez!