Well Uchiha are suppose to have higher chakra reserves due to their bloodline trait.  They have the stamina/chakra to cope with the sharingan.  Also 4 clones isn't really that many, also I should point out when one of the clones is destroyed the chakra used on that clone goes back to the original.  Relaying information and experience back to the original as well.   Also Tenshi's jutsus he has only 4 of them.  Only 2 are chakra based, the others are dirty tricks that utilized Taijutsu.

I didn't think 4 was that big of a deal it would be splitting his chakra into  1/5th of its original until one is destroyed or under the jutsu is undone.  I could lower the number if it really matters though, I didn't see 4 as a big number.  Considering running right at a jounin.  The four will be turned into a very low number really quickly I would think.